The Evil Electric Kingdom Nejirejia (邪電王国ネジレジア Jaden Ōkoku Nejirejia?) are invaders from another dimension ruled by an entity called Javious. Their names and appearances are all twisted and distorted. They are stationed in the Gran Nejiros (グランネジロス Guran Nejirosu?) fortress which transforms into the giant robot Death Nejiro (デスネジロ Desu Nejiro?, 51) in the series finale. This robot can regenerate severed limbs as well as bind and electrocute his victims with cables and was finally destroyed along with the Mega Voyager in the finale. Hinelar self-destructed the Death Nejiro from the inside in an attempt to blow up the Megarangers and the Mega Voyager. The Megarangers nearly sacrifice themselves to carry Death Nejiro with the Mega Voyager into the sky to prevent any damage to the city.
Evil Electro-King Javious I (邪電王ジャビウス1世 Jadenō Jabiusu Issei?, 2-43) is the ruler of Nejirejia. He appears only as a giant eye on the screen of the Gran Nejiros. Very little is known about him and he is killed when the last of the Nejirangers, whose life forces are connected to his, are destroyed by the Megarangers. Upon his death, Javious was revealed to be the nucleus of Nejirejia, which fades away upon his death. Only Javious' heart remained, which Hinelar used to power his Hinelar City.
Dr. Hinelar (Dr.ヒネラー Dokutā Hinerā, Twisted?) is the leader of the Nejirejia invasion party. He was originally a cybernetics scientist named Dr. Samejima (鮫島博士 Samejima-hakase?), who studied space exploring suits and lost his beloved daughter in one of his experiments, destroying his reputation and scarring him. He later worked with Kubota on an interdimensional project, being the first to discover the existence of Nejirejia. A year later, Samejima decides to enter the dimension to prove its existence in spite of Kubota's pleas not to be reckless and ends up becoming Javious' right-hand man. Kubota later realized that Dr. Hinelar and Samejima are one and the same when he recognizes that the suits of the Nejirangers are similar to the Power Suits Samejima had developed. Hinelar later plots and successfully kills Javious through the Nejirangers, to become the new high leader of the Nejirejians. After the destruction of Javious, the nejire dimension closes making Hinelar build Hinelar City (ヒネラーシティ Hinerā Shiti?) in which he intended to concentrate all mankind as data cards. Soon after the destruction of his city, Hinelar began his personal attack on the Megarangers after learning their identities and making sure that become outcasts to society. But Shibolena's demise drove Hinelar over the edge gained a second 'fighting' form to battle the Megarangers himself. However, the device that kept his body from warping on itself (a side effect from being in Nejirejia) was damaged and he retreated into the Gran Nejiros and turning it into Death Nejiro. When Death Nejiro exploded during the Mega Voyager's sacrifice, Hinelar dies, still inside while trying to will his body from collapsing onto itself.
Shibolena (シボレナ Shiborena, Squeezing?, 1-50) is a cybernetic gynoid modeled after Hinelar's long dead daughter, Shizuka. Considers herself the masterpiece of Dr. Hinelar's work. She was second-in-command to Hinelar on the Gran Nejiros, a mistress of disguise and illusions. Armed with a rapier, she was also the smart one, often initiating plans for conquest. Creating Bara Nejire through her own DNA, Shibolena poses as a nun to give her offshoot's roses to children, turning them into slaves and subject them to Akumatherapy (or Demon Therapy) to create "Petit Bara Nejire". But with one of the children being her new friend Ruri, Chisato arrives and nearly exposes herself as Mega Yellow (whom Shibolena establishes a rivalry with) to wound Shibolena with her Blade Arm. Fortunately, Mega Blue creates a holographic duplicate of Chisato to confuse Shibolena.
She was critically wounded near the finale, by Mega Red, while protecting Yugande. She makes it back to the Gran Nejiros, to inform Hinelar of Yugande's death. Her body explodes right before Dr. Hinelar's eyes after she say goodbye to her father.
Bibidebi (ビビデビ?) is a little annoying monster that begins his sentences with "Bibi" and ends them with "debi". In episode 2, Dr. Hinelar modified him with the ability to make the Nejire Beasts grow by biting them and injecting them with an Gigantification Virus (巨大化ウィルス Kyodaika Wirusu?) whenever they are destroyed or are nearing defeat at the hands of the Megarangers. In secret, Bibidebi wanted to be the head of Nejirejia and has some affection for Shibolena, secretly sending Canary Nejire to act on his behalf. He appears to have died in the Gran Nejiros when it was destroyed, by Mega Voyager's suicide attempt. Later, it is revealed that he teleported Hizumina out of the giant robot before the destruction.
Yugande (ユガンデ Yugande, Warping?, 1-8) is a prideful robot general created by Hinelar whom he admires and unconditionally obeys. Being high-strung, Yugande offers to handle the Megarangers himself. Using a divide and conquer strategy to take out the Megaranger members one by one, Yugande gets Mega Red to fight him in subspace so no one would interfere and nearly kills him before the others manage to breech the barrier. Mega Black is badly injured as they get their teammate to safety. Later, Yugande calls Mega Red out, attacking him in his enlarged form as the others arrive to aid him. Using Galaxy Mega, the Megarangers weaken him with the Saber Electromagnetic Whip before killing him with the Mega Side Cutter. However, Yugande is later rebuilt through the Nejire Circle in a stronger form, Yugande Strong (ユガンデストロング Yugande Sutorongu?, 9-31). But as he needs to get used to his upgrade, Yugande remained on the sidelines until the "Ultimate Lifeform" incident, attempting to extract revenge on Mega Red while the monster feeds. Though he manages to destroy Mega Red's Drill Saber and nearly kills him, Yugande is driven off by the Megarangers' Multi-Attack Rifle.
Later, he was critically wounded in Episode 30 when Guirail uses him as a shield to protect him from the Super Galaxy Mega's Super Galaxy Knuckle. Yugande has to be modified with various mechanical implants placed on him in order to survive, and is given a better sword called the Dark Crisis (ダーククライシス Dāku Kuraishisu?), which has three buttons on its handle to activate different attacks such as Dark Blade, Dark Fire, Dark Lightning, and Dark Triple Crisis (all three attacks combined). Yugande uses a special chip to take on a more powerful, red-colored form called Burning Yugande (バーニングユガンデ Bāningu Yugande?, 50). With this new power, Yugande proves to be a difficult challenge for the Megarangers, as he destroys the Delta Mega, badly damages the Galaxy Mega and Mega Winger and nearly destroys the Voyager Machines when he damages the INET moonbase. Yugande, however, meets his end when the Neji reactor inside him is damaged and he is killed by Mega Red.
Guirail (ギレール Girēru, Cutting?, 19-32) was one of Javious's trusted minions, he is sent to Earth to aid Hinelar with the Megarangers. Guirail used crueler methods than Dr. Hinelar's (an example of this is in his first appearance where he used children as shields), even performing unusual experiments on the Nejire Beasts. Prior to revealing himself to Hinelar's group, Guirail stages an attack to capture the children of a city district while breaking Kenta's will to fight by having him hit Takeshi by accident. However, while leading a new attack on a communication building, Guirail messes with Mega Red until he is beaten by him with the Battle Rizer. Later on, he parasited Yugande to become Giga Guirail (ギガギレール Giga Girēru?, 30). But when the Super Galaxy Mega used its Super Galaxy Knuckle attack, Guirail cancelled out the fusion to use Yugande as a shield to protect himself. An angry Shibolena trys to kill him but Dr. Hinelar stopped and tricked Guirail into taking the NejiGen Capsule that gives him tremendous power and robs him of his sanity. This mutated Guirail into an insane beast called Mad Guirail (マッドギレール Maddo Girēru?, 31-32) who was so powerful that the Super Galaxy Mega was no match for it. Usin full power the Galaxy Mega only caused him to break off a piece of his body that formed into Gigire (ギギレ Gigire?, 31-32), who could fly through space and blast a powerful laser from his forehead. The Megarangers were able to escape to the INET moonbase on the Delta Mega where Yuusaku gave them the Voyager Machines. In the end, Gigire, and later Mad Guirail, were the first two to be killed by the Mega Voyager.
The Jaden Sentai Nejiranger (邪電戦隊ネジレンジャー Jaden Sentai Nejirenjā?, Evil Electric Squadron Nejiranger) (38-43, 48) group were created by Dr. Hinelar from Javious' DNA as evil counerparts to the Megarangers. Their suits are similar to power suits Dr. Hinelar had developed back when he was known as Samejima. They share an attack called Neji Energy Attack. Unfortunately, the Nejirangers were impatient and wanted nothing more than to kill their Megaranger counterparts. The Nejirangers were used by Hinelar not only to kill the Megarangers in suicide attacks, but also to kill Javious by slowly draining him of his "life energy". When badly damaged or enlarged, they transformed into their monstrous true forms. The Nejirangers' urge to kill managed to keep them from dying as they used Hinelar's data-card machine to regain physical form. They not only resume their original goal but also to try to kill Hinelar for using them in the first place. The Megarangers manage to digitize them, preserving them as Data Cards in the now destroyed Hinelar City. Hinelar found the cards soon after the city was destroyed and sent them to where no one would ever find them.
- Neji Red (ネジレッド Neji Reddo?, 38-43, 48): Leader, armed with Neji Saber (ネジセイバー Neji Seibā?). True form, Neji Phantom (ネジファントム Neji Fantomu?, 42-43, 48), is a fire-like monster. Once turned on Dr. Hinelar when he discovered that the Nejirangers were mere pawns in Hinelar's plans, but had his free will removed. Killed by Super Galaxy Mega, Mega Voyager and Mega Winger, later turned into a Data Card.
- Neji Black (ネジブラック Neji Burakku?, 38-43, 48): The fiercest member of the five. Armed with Neji Rod (ネジロッド Neji Roddo?). True form, Neji Vulgar (ネジヴァルガー Neji Varugā?, 42-43, 48), is a rock-like monster. Killed by Super Galaxy Mega, Mega Voyager and Mega Winger, later turned into a Data Card.
- Neji Blue (ネジブルー Neji Burū?, 38-41, 48): Armed with Neji Tomahawk (ネジトマホーク Neji Tomahōku?). The most sadistic of the five, he became obsessed with specifically fighting and killing Mega Blue. True form, Neji Bizzare (ネジビザール Neji Bizāru?, 41, 48), is a crystalline monster. Killed by Wing Mega Voyager, later turned into a Data Card.
- Neji Yellow (ネジイエロー Neji Ierō?, 38-43, 48): Armed with Neji Sling (ネジスリング Neji Suringu?). The most cunning member and rival of Neji Pink. True form, Neji Sophia (ネジソフィア Neji Sofia?, 42-43, 48), is a lizard/hornet monster. Killed by Super Galaxy Mega, Mega Voyager and Mega Winger, later turned into a Data Card.
- Neji Pink (ネジピンク Neji Pinku?, 38-40, 48): The most brutal member, armed with Neji Arrow (ネジアロー Neji Arō?). True form, Neji Jealous (ネジジェラス Neji Jerasu?, 40, 48), is a plant-like beast. Killed by Mega Voyager, later turned into a Data Card.
Hizumina (ヒズミナ Hizumina, Distortion?, Gingaman vs. Megaranger) is the last of Hinelar's creations and Shibolena's "Younger Sister", mostly identical save for her armor being purplish. She secretly wished to revive Hinelar having grown to miss him with Shibolena's memories, but was betrayed by Gregory when participating in reviving the Balban space pirates. Surviving the treachery, Hizumina attempts to take adventage of the fight to kill the Magirangers, only to be ultimately killed by Mega Red.
Soldiers Kunekune (兵士クネクネ Heishi Kunekune?, Soldiers Wriggling) are Nejirejia's grunts, having twisted faces and using twisted blades as their weapons. They are also able to assume human form.
Boss Kunekune (ボスクネクネ Bosu Kunekune?, 14): A black-headed version of the Kunekune able to fire energy from his hands. Posing as a police officer, Boss Kunekune leads his Nejire Army into taking over the Yuuhigaoka Apartment building in the H Ward as part of a plan to secretly replace every person on Earth with Kunkune. When Megarangers uncover the plan, the Kunekune attempt to kill off Mega Red and Mega Pink with their massive numbers before Boss Kunekune arrives to finish them off. However, after being defeated by Mega Red's Drill Sniper Custom, Boss Kunkune calls his army to group around him to form King Kunekune (キングクネクネ Kingu Kunekune?), with his head in the heart area. Because he was composed of many Kunkune, King Kunekune could close wounds in seconds. When Boss Kunekune was destroyed by the Galaxy Mega with the Booster Rifle, King Kunekune disassembled in the explosion.
Monsters created by Dr. Hinelar when a Nejire Egg, a capsule holding genetically altered DNA, is placed on the Nejire Magic Circle (Nejire Mahoujin) and exposed to great amounts of energy, twisting and twirling while Shibolena chants a spell, "Twist and Turn. Assume physical form". Once the process is complete, a Nejire Beast (ネジレ獣 Nejirejū?, Twist Beast) is born and fully matured. There is always some part on the body of the Nejire Beast that is twisted.
- EiNejire (エイネジレ EiNejire?, 2): The first Nejire beast to be sent down to earth, attacking the Musashi district. The EiNejire could fly through space as well as fire laser blasts from his eyes. Kenta held the monster at bay until the rest of team arrives. Wounded by Mega Red with the Drill Saber, EiNejire retreated into the NejiCrusher, killed off when Galaxy Mega destroyed the giant machine.
- SaiNejire (サイネジレ SaiNejire?, 3, 21): This Nejire could create earthquakes when he walked as well as drill through large buildings with the drill on his face. SaiNejire could also deflect blasts from the drill when it was spinning fast. SaiNejire was sent to flush out the Megarangers, attacking the CG Center where Shun was located. Though Kenta attempted to keep him way from Shun while he was saving his program, SaiNejire destroyed the disc when Shun decided to save Kenta and fight alongside the team. Though defeated by Mega Red's Screw Drill Saber/Saber Slash combo, Hinelar arrives with the modified Bebidebi to infect the Nejire Beast with the Enlarging Virus integrated in Bebidebi's DNA. In the end, the Galaxy Mega destroyed SaiNejire with Mega Flying Cutter.
- ChameleonNejire (カメレオンネジレ KamereonNejire?, 4): This Nejire was used by Shibolena to project her image across the internet with the digital camera on his shoulder, which in the process would take control of people and have them undergo "Nejirian Teaching" to make them into blood-thirsty sadists. After freeing Miss Nishiyama from the mind-control with Koichiro unconscious, Shun managed to pinpoint the address, only to fall into a trap as they were sucked into a pocket dimension where ChameleonNejire is omniponent as he electricuted the four. Koichiro managed to find the real location and battled ChameleonNejire, overwhelemed by the monster's cameoflage until Mega Black use Satellite Searcher to negate the effect and managed to free the others. The others arrived in time and used their Final Shoot attack to defeat the ChameleonNejire. Bedidebi arrived soon afterwards and infected ChameleonNejire into a giant, only to be killed by Galaxy Mega's Saber Electromagnetic Whip and Mega Dash Cutter. However, only the Nejire's arm remained with a shard from the MegaSaber in it.
- EbiNejire (エビネジレ EbiNejire?, 5, 21): This Nejire is able to launch his pinchers like boomerangs, had his DNA modified with the shard of the MegaSaber found from ChameleonNejire's remains, making his shell impervious to the Galaxy Mega's MegaSaber. He attacked the volcanic mountainside to lure out the Megarangers and allowed himself to be infected by Bedidebi. The programmed Galaxy Mega arrives, only to be overpowered as EbiNejire. Once the Megarangers regained control, the Galaxy Mega turned the tables and ripped the Nejire's whiskers off. Using the Saber Electromagnetic Whip, the Galaxy Mega grabbed EbiNejire and threw him into the volcano destroying him.
- ZouNejire (ゾウネジレ ZouNejire?, 6): This Nejire possessed superhuman strength, ideal for his mission to knock over an energy system tower in an act of terrorism. This results in the building's generator undergoing a meltdown that would destroy the city. With Miku in the tower, Mega Black and Mega Blue had to deal with ZouNejire while Mega Red and Mega Yellow used the DigiTank to get her and Shintaro out of the building before taking and cooling the energy rods to stop the meltdown. By then, ZouNejire was enlarged by Bedidebi and tore the tower down as the DigiTank escaped. With Mega Pink, the Megarangers formed the Galaxy Mega and defeated the Nejire with swift punches before killing him with Galaxy Mega's Mega Flying Cutter attack.
- HachiNejire (ハチネジレ HachiNejire?, 7, 21): A stealth Nejire Beast Shibolena sends into space to cause lightning to strike down on every major city in the world. This Nejire Beast could also shoot beams from his eyes and launch a barrage of Space Bees from his "hive blade" on his hand. As Mega Red and the others investigate the Van Allen belt, Kouchirou and Chisato uncover Shibolena's plan to use the mind-controlled staff at the Space Observation Center and other space centers to create an Attack Dispersion Net which HachiNejire would use to take out every city at one time. He is then blasted back to Earth with the Final Shoot and defeated with the Digital Combination. After being bitten by Bedidebi, HachiNejire battles Galaxy Mega and is destroyed by the Booster Rifle.
- KoumoriNejire (コウモリネジレ KoumoriNejire?, 9): A Nejire Beast that could manipulate sound and signals. KoumoriNejire uses his bats to burns a special soundwave into CDs that cause those who hear it to commit acts of violence without any memory of it as part of Shibolena's plan to perfect brainwashing of humanity. When Saeko learned of it and attempts to gather the CDs, Shibolena sends KoumoriNejire after her to force her to commit suicide. But Chisato manages to free Saeko from KoumoriNejire's hold before she joins the fight against him, overpowering him by using the Mega Sling to defeat him. After being bitten by Bedidebi, KoumoriNejire attempts to overpower Galaxy Mega with his soundwaves until Saeko's intervention allows Galaxy Mega to destroy Koumori Nejire with the Mega Cross Cutter. Koumori Nejire's remains were gathered and he was recreated as the stronger Neo KoumoriNejire (ネオコウモリネジレ Neo KoumoriNejire?, 10). With a series of female androids at his disposal, Neo KoumoriNejire provides them with flutes and send them across the world to play the Murderous Soundwave, an enhanced version of the Rage Soundwave. However, one of his robots, Number 167 who looks exactly like Shun's deceased mother, develops a mind of her own as a result of being hit by a truck. Attempting too destroy her, he is forced to fallback after Mega Blue overpowers her. Tracking his creation down, Neo KoumoriNejire uses his Murderous Soundwaves on the Megarangers until 167 comes to their aid and uses Shun's flute to negate the Nejire Beast's attack before she selfdestructs to protect him. Enraged, Mega Blue attacks Neo KoumoriNejire in full fury before defeating him with the Tomahawk Sniper. Once enlarged by Bedidebi, Neo Koumori Nejire is easily destroyed by Galaxy Mega's Mega Dash Cutter.
- BaraNejire (バラネジレ Bara Nejire?, 11): This Nejire was partially created from Shibolena's DNA, linking them via the rose on Shibolena's rapier. As a result, Bara Nejire could recover from any wound as long as Shibolena was all right. While Chisato goes off after Shibolena, the other Megarangers have a hard time fighting Bara Nejire who whips the Megarangers with her vines and blast them with her shoulder flowers. Deciding to finish the fight, Bara Nejire allows Bedidebi to bite her and she overpowers Galaxy Mega. However, when Mega Yellow destroyes Shibolena's rose, Bara Nejire looses her advantage and is destroyed by Galaxy Mega's Galaxy Lance.
- MoguraNejire (モグラネジレ MoguraNejire?, 12): This subterranean-combat Nejire builds a machine to attract a piece of a heat-guiding meteor to Tokyo in order to use its energy to destroy the city in one blow. Managing to overpower Mega Black, but losing a fragment of the meteor, Mogura Nejire falls back and later abducts Mr. Ooiwa and Mega Black. With Mega Black regaining his composure, he saves Ooiwa and fights Mogura Nejire as the others arrive and destroy Mogura Nejire's base. Mega Black then breaks Mogura Nejire's claws off and was about to kill him when Bedidebi intervenes and bites the Nejire Beast. With Mega Black piloting Galaxy Mega, Mogura Nejire is destroyed by the giant robot's Galaxy Lance.
- FukurouNejire (フクロウネジレ FukurouNejire?, 15): This Nejire could hypnotize people and blind/blast them with harsh rays from his large eyes. Fukurou Nejire infiltrates Gojounin Academy's Digital Research to brainwash the genius students through their monitors and have them build digital blueprints for a weapon of mass destruction, which he builds within the school's basement. Investigating the school as a favor to his friend Souichi, who is possessed by the Nejire Beast, Shun uncovers Fukurou Nejire's plan and fakes being hypnotized to sabotage the weapon. Enraged at being tricked, Fukurou Owl battles the Megarangers until they defeat him with the Digital Formation. After being bitten and bursting out the school, Fukurou Nejire battles Galaxy Mega. Improvising a counterattack, Mega Blue places a mirror coating on Galaxy Mega's Mega Shield to deflect the attack back at Nejire Beast's eyes before the robot uses the Mega Dash Cutter attack to finish him off.
- DokugaNejire (ドクガネジレ DokugaNejire?, 16, 21): A Nejire Beast that is fed Hinelar's Nejire Poison, a deadly toxin he is immune to, which takes effect after 24 hours. He is to spread it around to kill as many as he can. Dokuga Nejire flies around the city, distributing the Nejire Poison on his wings, with the Megarangers affected along with 10,000 people and have until 6 PM to find an antidote. After a brief falling out, the Megarangers regroup and manage to break off a piece of antenna as the poison takes effect on them with Mega Black managing to deliver the item to INET to prepares an antidote from the Nejire Beast's immunity. By the time the Megarangers almost lose to Dokuga Nejire without their Mega Suits, they receive the antidote. Using the Drill Sniper Custom and Multi-Attack Rifle, they defeat Dokug Nejire as Bedidebi arrives to bite him. After ripping off his wing and learning that his death would cover the entire city, Galaxy Mega takes Doukga Nejire into space and uses the Booster Rifle to destroy him.
- GamaNejire (ガマネジレ GamaNejire?, 17, 21): ANejire Beast that appears in Tochigi's Rindou Lake while the Megarangers were on a field trip as one of hundreds of eggs which Debidebi was sent to mature with a red-liquid acceleration gun and deal with the Megarangers through a blue-liquid retrograde gun. However, after Bedidebi drops the acceleration gun into the lake during the fight after blasting Miku with it my mistake, it causes one of the eggs to quickly mature. Armed with the acceleration and retrograde guns, Gama Nejire was about to mature his siblings when the Megarangers led by the enhanced Super Mega Pink arrive and destroy the eggs. After being spirited off by Shibolena, Gama Nejire decides to use his acceleration gun to cause a volcanic eruption to call out the Megarangers and extract his revenge on them. Suffering side effects from her enhancement, Super Mega Pink eventually arrives to her team's aid and teams with Mega Yellow to defeat Gama Nejire to return to normal. After being bitten by Bedidebi, Gama Nejire is caught off guard by Galaxy Mega's Super Denji Snake before being destroyed by the Mega Flying Cutter attack.
- KinokoNejire (キノコネジレ KinokoNejire?, 18): A Nejire Beast that appears in the Nasu Plateau to burn down a forest to in order for the Nejirejians to obtain a meteor that fell there years ago. Confronted by Mega Black, Kinoko Nejire battles the Megarangers until the forest boy's interfence drives them out of the forest. After having his wounds healed, Kinoko Nejire resumes his attack as a giant before Galaxy Mega appears destroy him with the Mega Straight Cutter attack.
- SasoriNejire (サソリネジレ SasoriNejire?, 19): A Nejire Beast used by Shibolena to use his stinger to brainwash the children Guirail captured for his plan to take out a communications building. Though held off by Guirail, Mega Red defeats Sasori Nejire with the Battle Rizer to break his hold over the children. Bitten by Bedidebi, Sasori Nejire is destroyed by Galaxy Mega's Mega Dash Cutter.
- WaniNejire 1 & 2 (ワニネジレ1 & 2 WaniNejire 1 & 2?, 20): Created by Shibolena, the Nejire Beast was modified by Guirail against her wishes to split into two separate monsters: The tail-armed Wani Nejire 1 and the head-armed Wani Nejire 2. Catching the Megarangers off guard, Wani Nejire fights them until Bedidebi bites him and then splits after being hit by Galaxy Mega's Mega Flying Cutter. The splintered monster overpowers Galaxy Mega until the completed Delta Mega arrives to even the odds as the two robots destroy the Wani Nejires with their fire power.
- MukadeNejire (ムカデネジレ MukadeNejire?, 21): A Nejire Beast used by Guirail in a plan to pirate Delta Mega with the Gran Nejiros. "Resurrecting" fallen Nejire Beasts, Mukade Nejire enlarges as his Zombies Nejires overwhelm the Megarangers to keep them from using Galaxy Mega and force Mega Red to call Delta Mega, springing Guirail's trap. Managing to form Super Galaxy Mega to break Nejirejia's hold over Delta Mega, the Megarangers use their newly formed robot to destroy Mukade Nejire and his Zombie Nejires.
- AirjigokuNejire (アリジゴクネジレ ArijigokuNejire?, 22): A Nejire Beast who uses the Mebius Ring staff to create two thousand Nejire Door dimensional portals across the city. As ArijokuNejire was about to insert a Nejire Crystal into the Mebius Ring to boost its power so the portals can spread across the world, the Megarangers intervene with MegPink unknowingly taking the crystal before she and MegaBlue are blasted into a Nejire Door. ArijigokuNejire chases after Shin and Miku to across the Nejire Doors while Yugande and Shibolena deal with the other Megarangers. Though Nejire Beast manages to get the crystal back, the Megarangers destroy the staff before defeating him with the Drill Sniper Custom/Multi-Attack Rifle combo attack. Bitten by Bebidebi, an enlarged ArijigokuNejire takes Galaxy Mega to another dimension to bury the robot before Delta Mega arrives to save Galaxy Mega before they combine and destroy ArijigokuNejire.
- AnkouNejire (アンコウネジレ AnkouNejire?, 23): A Nejire Beast that Bibidebi personally created, possessing super speed and can shoot a petrification beam from his lure. AnkouNejire has a younger brother whose egg is sent to Earth for being of no use. The egg ended up in Kenta's possession, hatching under his care and then named Komutan. But on the notion that the NejireBeast's absorbing of his sibling would increase his powers to turn matter into diamond, which can be used to power their weapons, Guirail sends AnkouNejire to Earth to find his brother. Finding Komutan, Ankou Nejire manages to absorb Komutan and alters his brother's behavior under his influence. However, Kenta manage reach Komutan and give him the strength to free himself. After killing Komutan for attacking him, MegaRed uses the BattleRiser to defeat. Bitten by Bebidebi, an enlarged AnkouNejire's lure is blasted off by Delta Mega before he is destroyed by Super Galaxy Mega.
- BuffaloNejire (バッファローネジレ BaffarooNejire?, 24): A Nejire Beast created by Yugande, labeled as one of the strongest NejireBests. Sending a dummy of BuffaloNejire to attack, Yugande uses it to record data on the Megarangers' attacks on the gem on its head. Once the dummy is blasted to bits, the gem is teleported back to the Nejiros to be inserted into the real BuffaloNejire. The next day, BuffaloNejire begins his attack before the Megarangers intercept him. But with the gem on his head, BuffaloNejire could deflect the Megarangers' attacks. However, when MegaSilver makes his debut, BuffaloNejire's gem is unable to defend him from the Megaranger's attack before being defeated with MegaSilver's Blazer Impact. Bitten by Bebidebi, overpowering Galaxy Mega, an enlarged BuffaloNejire is destroyed by Super Galaxy Mega.
- UtsuboNejire (ウツボネジレ UtsuboNejire?, 25): A Nejire Beast created by Dr. Hinelar, armed with a trident and able to spew acidic sludge from his mouth. After testingthe NejireBeast's ability to convert surrounding water into poison, Guirail proceeds to clone UtsuboNejire so the entire ocean would become a sea of death. After UtsubouNejire and his clone capture the Megarangers, MegaSilver destroys Guirail's lab. As the Megarangers defeat the clone with the Riser Punch before destroying him with Super Galaxy Mega, MegaSilver ensures UstuboNejire is not enlarged as well before destroying him.
- SemiNejire (セミネジレ SemiNejire?, 26): A Nejire Beast who can use sound wave attacks. Possessing the body of Professor Tadashi Nanba, a scientist the Nejirjians kidnapped, SemiNejire and Guirail staged the scientist's escape and possession of a Nejire-negation device to trick I-NET into installing the system into the NOA Space Communication Center. By the time Kouchiro realizes something is wrong when "Nanba" refused to see his wife and child by that time, the system is complete and SemiNejire slaughters the NOA scientists. Discarding his host, SemiNejire reveals that the system's true function is to send hyper waves that destroy the human brain within ten minutes. However, with Yusaku's help, Kouchiro manages to hold off SemiNejire so I-NET can disable the Hyper Wave Emitter System. Defeated by a Blazer Impact/Rod Break combo before being bitten by Bebidebi, SemiNejire is destroyed by Super Galaxy Mega.
- SangoNejire (サンゴネジレ SangoNejire?, 27): A Nejire that could slowly transform people into coral, which would eventually kill them in the process. Killed by Super Galaxy Mega.
- ShiroariNejire (Female) (シロアリネジレ (メス) ShiroariNejire(Mesu)?, 28): A Nejire who could lay eggs and power them up to grow quickly. Killed by the combined efforts of Mega Red, Mega Black, Mega Blue, Mega Pink and Mega Silver. Her larvae, however, hatched and fused together to become Soldier ShiroariNejire. This Nejire was stronger that his mother, and could turn into a swarm of termites to eat through anything (including the Megarangers weapons) and/or avoid the Megaranger's attacks. Killed by Super Galaxy Mega with a combination of using the Booster Rifle set on freezing gas and then using Super Galaxy Knuckle.
- ButaNejire (ブタネジレ ButaNejire?, 29) A monster who created and sold special "Diet Crêpes", while disguised as a chef, that actually induced people to eat anything nearby. While a formidable monster, ButaNejire's weakness was hunger. He would abandon a fight, even if he was winning, to look for food if he became hungry. Killed by Super Galaxy Mega.
The Psycho-Nejilars (サイコネジラー Saiko Nejirā?) are more powerful robotic monsters, created by Hinelar using Mad Guirail's remains in the Nejire Beast creation process, that were used following the debut of the Mega Voyager. They differ from the Nejire Beasts due to their heightened psychotic natures and metallic bodies.
- Lion Nejilar (ライオンネジラー Raion Nejirā?, 33, Megaranger vs. Carranger): A superstrong Psycho-Nejilar who could blast the Megarangers with his large cannon and could detonate bombs if the Megarangers attacked him. Mega Red, with an upgrade to his Battle Raizer, was able to use this new energy to power up his Drill Sniper Custom into the Super Drill Sniper Custom, allowing him to kill Lion Nejilar before he could detonate any of his bombs. Killed by Mega Voyager. Was resurrected by Kani Nejilar, killed by the Mega Tector powered Megarangers.
- Yamaarashi Nejilar (ヤマアラシネジラー Yamaarashi Nejirā?, 34, Megaranger vs. Carranger): A Psycho-Nejilar who could turn soccer balls into explosive devices and kick them at humans to blow them up. Was resurrected by Kani Nejilar, killed by the Mega Tector powered Megarangers.
- Kamakiri Nejilar (カマキリネジラー Kamakiri Nejirā?, 35, Megaranger vs. Carranger): A Psycho-Nejilar that took advantage of Mega Silver's short transformation weakness by affixing a time bomb to him set to go off when he reverted to normal. However, Mega Silver managed to upgrade his powers so he no longer had the time limit and was able to defeat him. Killed by Mega Voyager. Was resurrected by Kani Nejilar, killed by the Mega Tector powered Megarangers.
- Condor Nejilar (コンドルネジラー Kondora Nejirā?, 36, Megaranger vs. Carranger): A Psycho-Nejilar that could fly really fast and blast enemies with his beak lasers. This battle brought out the debut of the Mega Winger. First to be killed by Wing Mega Voyager. Was resurrected by Kani Nejilar, killed by the Mega Tector powered Megarangers.
- Canary Nejilar (カナリアネジラー Kanaria Nejirā?, 37): A Psycho-Nejilar that had an "exchanging beam," allowing him to swap something he had for something someone else had, like his "old man" voice for Chisato's voice and goofy objects for the Megarangers' weapons. Canary Nejilar was sent by an unappreciated Bidebedi and stole Chisato's voice. Killed by Wing Mega Voyager.
- Tokage Nejilar (トカゲネジラー Tokage Nejirā?, 39, Megaranger vs. Carranger): A Psycho-Nejilar who could photograph the Megarangers through their helmets threatening to blackmail them, although it didn't work. He could also blast lasers from his mouth. Killed by Wing Mega Voyager. Was resurrected by Crab Nejilar, killed by the Mega Tector powered Megarangers.
- Kani Nejilar (カニネジラー Kani Nejirā?, Megaranger vs. Carranger): A Psycho-Nejilar who could fire high-pressure water cannon concealed in his claw in his "Kani Bubble" attack with a strong shell on his back that could deflect his opponent's attacks. He was created to assist Yugande in obtaining the power emitting from Picot, only to be teamed up with Helmedor after the Nejirians learn more about Picot. Despite Helmedor's betrayal, Kani Nejilar uses Picot to revive his predessors. Defeated by the Mega Tector powered Megarangers and bitten by Bebeidebi, Kani Nejilar is destroyed by Wing Mega Voyager.
- Togebari Nejilar (トゲバリネジラー Togebari Nejirā?, 45): A Psycho-Nejilar whose power grew stronger from the thorns on his hand. It attached a small , mind-controlling earring to people, including Kenta and his classmate Shintaro, causing them to serve Dr. Hinelar and attack their friends. This happened until Kouchiro and the others destroyed the earrings. When Thorn-Needle Nejilar's thorns were destroyed, he lost most of his power and was able to be killed by Mega Voyager.
- Maboroshi Nejilar (マボロシネジラー Maboroshi Nejirā?, 46): This Psycho-Nejilar could make himself disappear and reappear in various locations. At one point, he confused the Megarangers by going to the southern end of Japan, and then back to Sapporo only to appear behind them afterwards. Killed by Mega Voyager.
- Tenso Nejilar (マボロシネジラー Tenso Nejirā?, 47): A Psycho-Nejilar who could suck up earthlings in his vacuum-like laser and transport them into Hinelar City. Killed by Mega Voyager.
- Jigoku Nejilar (ジゴクネジラー Jigoku Nejirā?, 49): A bat/grim reaper designed Psycho-Nejilar who was created to force the Megarangers to expose themselves in their High School, which they did. Though he died at the hands of Mega Voyager, he managed to turn the heroes' schoolmates and friends against them.
- Neji Crusher (ネジクラッシャー Neji Kurasshā?, 1-2): Sphinx-like spaceship that utilized a warp-gate to materialize in "our" world (and made a sound effect like a dematerializing TARDIS in the process). Could blast lasers from its tail. Destroyed by Galaxy Mega.
- Ultimate Lifeform (究極生命体 Kyūkyoku Seimeitai?, 13): The result of the Tanaka Project to produce an artificial creature which can endure in outer space and feed on energy from its feelers, almost all research relating to the entity was destroyed except a pendant containing a IC Chip holding the DNA sequence. After Shibolena acquires it, she use the data to create a Nejire Beast so that it would destroy humanity after absorbing enough electricity. After losing one of its feelers to the Megarangers, the Ultimate Lifeform enlarges and battles Galaxy Mega until it is destroyed by the robot's Mega Flash Arrow.