Armadeevil
Armadeevil is a rat-faced Nighlok with a hard snail-like shell. His existence was unknown to Master Xandred before he came to the ship and offered his services. He merrily goes on a rampage, and the Samurai Rangers are unable to cause him any damage due to his armor plating. They are only granted a reprieve by his need to rehydrate. When he returns, they are able to weaken his shell by first tricking him into crashing into a rock wall and then by super-heating it and quickly dousing it with cold water afterward to induce thermal shock. Armadeevil is then destroyed by the Blue Ranger/Super Samurai Mode's Super Spin Sword Slash Finsher.

He grows large and the Rangers form the Samurai Megazord. Afterwards, the Samurai Megazord is able to use its Samurai Strike Finisher on Armadeevil. After Armadeevil withstands the Samurai Strike, the Rangers repeat their strategy against his giant size. The Rangers use the Beetle Blaster, Swordfish Fencer, and the Tiger Drill Megazord configurations but to no avail. The Rangers use the Claw Armor Megazord Formation and use its Double Katana Strike Finisher, but even this is unable to damage Armadeevil. This forces the Rangers to resort to the artillery cannon which finally destroys Armadeevil.
Shell Game

Switchbeast
Switchbeast is a cat-like Nighlok. He can switch the spirits of anyone and place the original spirits in a different object. Switchbeast arrives at Master Xandred's ship and states that he was sent by a powerful Nighlok to assist him. When he first fought the Rangers, Switchbeast placed Jayden's spirit into a garden gnome, Kevin's spirit into a ballerina music box, Mia's spirit into a fan, and Antonio's spirit into a fish he was going to eat. Switchbeast also traps the spirits of people at a public market (including Bulk and Spike) in some of the items they were selling. Switchbeast does this to have the humans "recycle" his victims without knowing it, which will cause the misery of the people he switched to raise the Sanzu River.

Mike and Emily manage to switch Switchbeast's spirit with Mike to make him force the spirits of everyone back into their own bodies. This works as even the Samurai return, but unfortunately Antonio is traumatized when he escapes just as a stray cat is about to eat the fish he was in. Switchbeast is then defeated by the Green Ranger/Super Samurai Mode. When Switchbeast grows, the two Rangers must pilot their Claw Armor Megazord which they use to destroy Switchbeast. In "Something Fishy," it was revealed that Switchbeast was associated with Serrator.
Trading Places

Eyescar
Eyescar is a one-eyed Nighlok that was founded by Octoroo. He is said to have resided in the deepest parts of the Sanzu River and Octoroo found him upon the strange bubbles coming to the surfaces. He assists Octoroo in kidnapping Antonio and Mentor Ji in order to lure the Rangers to his army of Moogers. After most of his Moogers were destroyed, he took on Red Ranger himself who defeated him using the new Shark Attack Mode. He grew giant and took on the Samurai Megazord and Claw Battlezord. Later, the Rangers used the new Shark Zord. Eyescar was defeated by the Claw Battlezord South and the Samurai Shark Megazord.
The Rescue
Crustor
Crustor is a barnacle-covered Nighlok. He wields a sword in battle and can breathe fire. Serrator gave Crustor the job to find the Bullzord so that it can be part of a bigger plot that he has planned. Crustor targeted a boy named Cody whose family had guarded the seal that contains the Bullzord in a plot to gain control of the Bullzord. Crustor follows Cody to where the Bullzord is sealed where he releases the Bullzord. When the Bullzord is freed and runs rampant, Crustor plans to find a way to capture the Bullzord and Cody. Crustor orders the Giant Moogers to capture the Bullzord and Cody unharmed with the Samurai Megazord and the Claw Battlezord competing against them to capture the Bullzord. When the Moogers fail, Crustor states that capturing the Bullzord will be tough enough. Crustor states to Master Xandred that he will go after the Bullzord again.

Crustor and the Moogers track the Bullzord and end up fighting the Samurai Rangers. Crustor proceeds to go after the Bullzord with Jayden on his trail. Crustor infiltrates the Bullzord as Jayden also enters the Bullzord where he fights Crustor. As Jayden fights Crustor, the Bullzord is heading straight towards the cliff. Upon knocking down Crustor, Jayden gives Cody a disk which combined with Cody's symbol power to tame the Bullzord while he continues to fight Crustor as Jayden assumes his Super Samurai Mode and knocks him out of the Bullzord. After the Bullzord is tamed, Crustor grows to giant size. After Cody gets to safety, Jayden ends up transforming the Bullzord into the Bull Megazord and Jayden transform into Shogun Mode. The Bull Megazord manages to destroy Crustor with the Revolving Laser Blaster and Final Strike attack.
The Bullzord

Skarf
Skarf is a Nighlok that can eat anything with his head-like hands and can also elongate his arms. Master Xandred and Octoroo find Skarf chomping on parts of their ship. Serrator states that Skarf will cause misery for the humans and that he has another type of power when he ends up destroyed in battle. Skarf then gnaws on Octoroo. Kevin finds Skarf feasting on different items in the park and ends up eating Kevin's Samurizer while saving a bicyclist. The other Power Rangers ended up fighting Skarf who ends up retreating after taking a hit from Jayden's sword attack. Skarf later returns and starts eating the City Center. The Rangers fight Skarf again. Mike uses his Samurizer to find Kevin's Samurizer in Skarf's right arm. Just then, Deker arrives to fight Jayden while the other Rangers fight Dayu and Skarf starts eating some of the nearby stuff. Dayu and Deker then attack Skarf which unleashes Skarf's true power.

As Skarf's true power is being unleashed, Jayden saves Kevin's Samurizer by cutting off Skarf's right arm. Skarf then grows into his second form where his arms are converted into two halves of a nearly impenetrable tiki-faced wall whose eyes shoot beams. With Kevin getting his Samurizer back, the Rangers summon the Claw Armor Megazord where it's attacks have no effect getting through Skarf's shield. Under Kevin's advice, the Rangers call all the Zords to them in order to combine all the Zords into the Samurai Gigazord which uses the Ultimate Samurai Slash to break Skarf's shield. The Samurai Gigazord then uses it's Mega Strike attack to destroy Skarf.
Kevin's Choice

Duplicator
A skull-faced Nighlok who can make duplicates of himself. He can also wield a sword and shoot shadow balls. Duplicator was sent to Earth by Serrator to cause misery. Duplicator arrives at the Norway Factory where he scares off the workers. The Rangers fight Duplicator who makes duplicates of himself that end up fighting the Rangers. The Rangers ends up having a hard time determining which of the clones is the real Duplicator. After knocking down the Rangers, Duplicator retreats due to him drying up.

The Rangers suspect that Duplicator's clones don't cast reflections and plan to use the Lightzord to enable them to find the real Duplicator. After replenishing himself, Duplicator attacks the city at night. The Rangers charge up the Lightzord as they fight Duplicator. Duplicator makes his clones to attack the Rangers until the Lightzord is fully charged. When Lightzord is fully charged, it shines enough light to give away the real Duplicator as Antonio breaks his sword and takes him down with his Blazing Strike. Mia assumes her Super Samurai Mode and defeats Duplicator with the Super Air Wave attack.

Duplicator then grows and the Rangers form the Claw Armor Megazord as well as summoning the Light Megazord. The Light Megazord uses it's jabs while the Claw Armor Megazord uses it's Double Katana Strike attack. When Duplicator makes duplicates of himself, the Light Megazord uses it's Double Disk Scatter Shot to destroy the duplicates as the Claw Armor Megazord uses the Samurai Battle Cannon to destroy Duplicator.He can make millions of himself.His face is like a skeleton.He is one of Serretors monsters.In the game at nicktoons Duplicators name was actually Dorbukara.He has shadows of himself.
Runaway Spik

Grinataur
Grinataur is a large-mouthed Nighlok. He can shoots black sand out of his tongue that can make people hungry or thirsty as well as emitting energy balls. Grinataur used his hunger-inducing powers on most of the Rangers (except for Emily who was going through some doubts) as well as some other humans. When Grinataur returned, Jayden ended up fighting Grinataur until Emily arrived. Grinataur tries to use his hunger-inducing sands on Emily only for her to conjure a wall. Using the Black Box, Emily managed to defeat Grinataur enough to negate his power on everyone. Grinataur grows as the other Rangers arrive and form the Samurai Gigazord. After Emily temporarily disengages the Apezord from the formation to cause a diversion on Grinataur, the Samurai Gigazord manages to destroy Grinataur.
The Strange Case of the Munchies
Epoxar
Epoxar is a Nighlok. He is able to shoot a special glue from his shoulder which remains sticky unless if Epoxar is destroyed. He can also shoot beams from his eyes and wields a fork-like weapon. He first appears to attack the city where he ends up attacking the Rangers. Mike and Kevin try to double-team him only for Expoxar to glue their hands together. Antonio arrives and attacks Epoxar enough for him to retreat. Epoxar is scolded by Master Xandred for retreating only for Serrator to intervene telling them that two of the Rangers are in a "sticky situation." Octoroo then tells Epoxar to stick some humans together in order to draw the other Rangers to him. He starts by using his glue on Bulk and Spike. Epoxar continues his attack on the city. Epoxar completes his Ranger Trap as the other Rangers head to where Epoxar is.

The Rangers end up chasing Epoxar into his Ranger Trap and then quickens the paste so that they won't be able to stop him from destroying the city. Mike and Kevin had to get in synch in order to fight Epoxar starting with them throwing a shopping cart to protect some people from the glue attack. Mike and Kevin use their attacks in double mode until they use the Forest Spear and Hydro Bow to take down Epoxar which undoes the glue he did on everyone. Epoxar then grows as the Rangers arrive with the Bull Megazord, the Claw Battlezord North, and the Lightzord. The Bullzord counters Epoxar's glue attack as the Claw Battlezord North uses it's Octospear. The Bullzord uses the Revolving Laser Blaster to destroy Epoxar.
A Sticky Situation

Malden
A Nighlok who assisted Master Xandred and Octoroo into testing the Master Blasters for the Moogers. Once the test was complete, Malden rendezvous with Serrator on the island of Monalua where he and the Moogers use the Master Blasters on the Samurai Rangers. He managed to knock down Antonio. In the nick of time, Mentor Ji arrived with the new Bullzooka created by Cody's family as Jayden uses the Bullzooka to take out the Moogers. Malden then uses his Master Blaster to fight Jayden.

Jayden uses the Bullzooka's Bullzooka Blast to defeat Malden who commented that this wasn't part of the plan. Malden then grows as the other Rangers use the Bull Megazord and the Lightzord fight Malden while Jayden tries to exterminate the paranoid. Malden is assisted by Giant Moogers to use the Super Master Blaster on the Megazords. After the Giant Moogers were defeated, the Lightzord then disarms Malden as the Bullzord uses it's Revolving Laser Blaster to destroy Malden.
Trust Me

Pestilox
Pestilox is a Nighlok that serves Serrator. Pestilox had a swarm of flies that caused stomach pain on everyone if they swallowed them and can also emit tentacles. Destroyed by the Claw Armor Megazord and Samurai Battle Cannon.
A Crack In The World
Trickster
Trickster is a Nighlok that is covered in dice and has eye-mounted hands where his eyes should be. He wields a two-bladed staff, can trap people in their nightmares which he controls, and emit a Dream Beam. Destroyed by the Claw Armor Megazord.
Trickster Treat
Fiera
Fiera is a bird-like Nighlok with a lobster claw for a right hand. She has the ability to disappear and appear with ease. Destroyed by the Lion Foldingzord.
Fight Fire With Fire
Gigertox
Gigertox is a Nighlok with stretchable tentacles that can grab anybody. After being powered up by Octoroo he gains a third life as a giant snake monster made of a dark mist. Destroyed by the Samurai Gigazord.
The Great Duel
Gred
Gred is a Red and Green faceless Nighlok with 6 dots for eyes that the Rangers fought on Christmas. Destroyed by the Battlewing Megazord.
Stuck on Christmas