The Mutants were Demons who turned into the Monsters by Hades and Senator.
Iguanaster was possessed by the demon who fought the Rangers that has red eyes, long tail and sharp-pointed teeth. His ability is to stick his tongue at the Rangers as well as jumping from the ground. He was eager to defeat the Rangers, however, they defeated him with Automotive Cannon. With the help of Rachel, she gave the Rangers a Limo Bullet. He was not strong enough to defeat the Rangers. He later returns after he was revived by Miss Parasitism, eventually he grown the giant form to get revenge on Rangers. He was destroyed once again by Nitro Megazord.
Bulldogger is possessed by the demon who fought the Rangers. He was based on Pit bull dog and werewolf who attempts to kill the citizens (especially adults and children). He can bite people to injury to death in 10 minutes. The Rangers rescue the children and evacuate them safely. Suddenly the he was beaten by the Rangers and Automotive Cannon. He was not finished yet, he was grown into giant to squash people to kill them. It was the worse part that he was dangerous monster. Nitro Megazord attacks him few times with a sword. He was destroyed by Nitro Megazord but never know the citizens will never get a bitten a pit bull monster.
Centipedealer is Centipede who was possessed by a Demon who fought the Rangers. He has 100 legs looks similar to Rantipede from Jungle Fury and black suit with white dress shirt. He was brown and black centipede monster to defeat the Rangers. Rachel manage to help the Rangers to defeat Centipedealer by destroying his energy. Centipedealer was grown into giant, he was not taking advantage to defeat the Rangers. He was beaten by Limo Battlezord and destroyed by Nitro Limo Megazord.
Rocky is the monster who was possessed by the Demon. He was brown stone golem monster. He can punch the Rangers with his fist. Rocky attempts to destroy Rangers but Senator demanded him. He can tossed the Rangers against the wall. He was not weak after all. Hades and Senator congratulates him for finishing up the Rangers for good. The Rangers hasn't give up yet, they defeated him using an Automotive cannon to destroy him. Rocky is grown into giant with absorption of all the rocks and stones. He began to attack Nitro Megazord as well as Limo Zord, in order to defeat this monster, the two Megazords can combine into Nitro Limo Megazord. Rocky was finally destroyed for good.
Apezilla is the monster who was possessed by the Demon. He was an Gorilla with 8 pack of abs, muscular arms and legs and Chest armor. He fought the Rangers and Military Rangers. Apezilla can throw bananas as a boomerang at the Rangers. With the help of Senator and Chaos Knight, he wants them to make him powerful to defeat the Rangers. If the Rangers decide to combine their powers to become super ability to defeat Apezilla by using the Automotive Cannon. However, Apezilla has grown himself into giant size after eating all his bananas. Nitro Megazord and Military Megazord attempts to destroy Apezilla, he's too powerful. Nitro Megazord combines with Military Megazord into Override Megazord, eventually began to fight Apezilla. He was officially destroyed by Override Megazord.
Vulturer is the Birds of Prey monster who was possessed by Demon. He has Greyish-black vulture with yellow and green talon feet, feathers that are stealth and beak is orange and yellow. He fought the Purple Ranger who was new girl. The Rangers convince Claire that they can sit this one out if they are not strong enough to defeat Vulturer. Claire defeats him with her weapons. Vulturer was not done yet, as he grew giant-size to defeat the Rangers. Claire summons Van Zord but Nitro Megazord waits for help. Vulturer's wings is damaged, he was destroyed by Nitro Van Megazord.
Tusk was the monster who was possessed by a Demon. He was the grey Walrus with legs are long, large arms and sharp teeth pointed. He fought the Rangers (especially Blue Ranger). It was then Richard decide to defeat Tusk with Truck Hammer. He was been taught a lesson from the Blue Ranger. He began to grown himself to defeat the Rangers. With the help of Blue Ranger, he summons the Altima Zord to combine with Nitro Megazord. Tusk was destroyed by Nitro Altima Megazord when he was tossed on the ground.
Speedster was the monster who was possessed by a Demon. He was white rabbit monster with red eyes and sharp teeth who likes to run faster. He the male Yellow Ranger as well as the other Rangers. Yellow Ranger attempts to catch Speedster but he's too fast to defeat him. Randal runs to catch him to attack him but it was not working out. Randal and Claire helps each other out to defeat Speedster to use regeneration. Speedster comes back to battle the Rangers but before Randal has an idea, he and Claire attacks Speedster and other Rangers to proceed to defeat him. Speedster was in bad shape a little bit. He has grown himself into giant size. Nitro Megazord attacks Speedster but he dodged and ran away. Randal summons and drive the Bus Zord, and transform into the Nitro Bus Megazord as rollerskates. Nitro Bus Megazord destroys Speedster with one final blow.
Scorpionix is the monster who was possessed by the Demon. She was black and orange scorpion with pincer arms, two legs other six legs are other arms and green eyes. She fought the Rangers. She kidnaps the Jade, Katrina and Rachel when they were defeated, while the Rangers attempt to stop her. She escapes with captive Rangers. She thinks that Hades is pleased that she capture the Rangers and put them into prison cell. Suddenly, The Rangers rescue the other Rangers after distracting Scorpionix and they escape. She attempts to chase the Rangers. After that, she was destroyed by Rangers and Automotive Cannon.
Croaker is the green frog monster who was possessed by the Demon. He was a ferocious amphibian creature monster. He fought the Rangers. He was often assist by Chameleonster. His ability to sting the Rangers with his tongue attack. Even then, he challenge Yellow Ranger to a duel. Chameleonster joins in to take out Randal with Croaker. Randal was easily defeated. The two have escaped from the battle. Croaker and Chameleonster are excited to defeat the other Rangers. Unfortunately, Randal wants a rematch from Croaker. He battles him with his Buggy Gauntlet. He was destroyed by Randal, but Chameleonster cries for help, Croaker growns himself to crush the Rangers. Nitro Megazord can combine with Bus Zord into Nitro Bus Megazord to destroy Croaker once and for all.
Coyoter was the monster who was possessed by the Demon. He is reddish-brown coyote monster with green eyes and grey nose. He was fought the female Green Ranger named Jade. He suddenly attack her by throwing her to the ground. He doesn't give up to defeat her. Jade must focus by learning to use a blaster to defeat the Coyote monster. Coyoter was defeated by Jade and the Rangers. In fact, he decide to grown himself into giant. Jade has an idea to summon the Camaro Zord to defeat Coyoter. Nitro Megazord uses Camaro Zord as a blaster to destroy Coyoter once and for all.
Gecko is somewhat monster who was possessed by the Demon. He was greenish-blue and purple reptile monster. He fought the Rangers to defeat them. He fights with the Green Ranger by tackling her in the stomach. Jade focuses to defeat Gecka in order to destroy him with her Air Daggers. He was not finished yet, he was grown into to destroy the Rangers. Nitro Camaro Megazord comes to kick Gecka's butt, he admit defeat before was historyed. Nitro Megazord fires the blasters at Gecka and finally destroyed him.
MissThorns is the pink and purple plant monster who was possessed by Demon who fought her enemy Pink Ranger. She has sharp-pointed thorns to attack the Rangers as well as Military Rangers. Katrina must find the way to defeat this monster is to use the sword to destroy her vines and thorns. She was beaten by the Pink Ranger. MissThorns has grown herself with the whole bunch of vines and thorns are restore and it was difficult to rip her vines. Pink Ranger has a surprise to use Wagon Zord to combine with Nitro Megazord. She was destroyed by Nitro Wagon Megazord and the chainsaw.
Octolossus is the giant octopus monster who was possessed by Demons along with Captain Octo. It has 20 tentacles, 2 legs, yellow iris eye and an angry grin on it's face. Captain Octo was planning to flood the city with the water, but the Rangers stop them for doing the ambitions. Captain Octo was defeated by Rangers, but he summon Octolossus after it was grown into giant. Octolossus starts destroying the city buildings and Captain Octo grown himself into giant as well. Rangers decides to use Nitro Wagon Megazord once again. Nitro Megazord uses the chainsaw slices numbers of Octolossus' tentacles and destroyed that monster. After that, Captain Octo will taste of his own medicine after he was destroyed by the Wagon Zord's chainsaw and Nitro Megazord.
Soarcon was possessed by a demon, he was a falcon that has big talon feet, strong wings with black and red stripe and large beak. He was attacking Jacob to injure him. Jacob can't stand it because he has no idea what to do. He was beaten by the Rangers. He was grown into giant. Nitro Megazord can't do anything without flying. The better way is the Blimp Zord connects with Megazord to form a jetpack. He was destroyed by Nitro Megazord jet pack mode.
Pterodactyl was possessed by a demon, he was a Pterodactyl that has arms, strong wings with legs. He was fought the Rangers. Jacob attacks him with his GT Sword. Pterodactyl is getting worn out somehow. He was beaten by the Rangers. He was grown into giant. Nitro Megazord summons Blimp Zord connects with Megazord to form a jetpack. He was history by Nitro Blimp Megazord.
Moledig is the underground demon who was possessed by the Demon. He was brown mole with the claws. He loves to escape from the Rangers by digging away. Truck Rangers assist Moledig to destroy the Rangers. Even though Chaos Knight join the fight and knock all the Rangers out all by himself. Moledig and the Truck Rangers join forces to fight with Military Rangers. He was distracted by the White Ranger to destroy him with her Limo Bullet and Automotive Cannon. While the Truck Rangers retreat, Moledig grown himself into giant. Rachel gives Military Rangers an advice to use Caravan Zord from after she bringing it in. Without Nitro Megazord, it's all up to Military Megazord to destroy Moledig. Moledig battles Military Megazord and he was destroyed by Military Megazord Shovel Mode.
Beetlelance was the monster who was possessed by a demon, he was Indigo Hercules Beetle that has four arms, and two legs. He was Miss Parasitism's friend and also a minion. Miss Parasitism and Beetlelance joins forces to take the Rangers. Together they worked to destroy the Rangers one by one. Somehow Miss Parasitism and Beetlelance defeats them to make sure that they can feel the pain. He was beaten by the Rangers a little bit but Chaos comes and defend him and Miss Parasitism. He thank Chaos for rescuing him from getting killed. He was defeated by Rangers and he grown himself into giant. BMW Battlezord helps Military Megazord to attack Beetlelance. He was destoryed by BMW Battlezord and Military Megazord. After that, Miss Parasitism cries, mourns his death and escape.