Kevin Levin

Kevin Ethan Levin (otherwise known as Kevin 11) is a prominent character in the Ben 10 franchise.

Appearance
In the original series, 11-year-old Kevin was a thin and scrawny boy with shoulder-length black hair, pale skin, and dark brown eyes with black markings around them. He wore a black T-shirt, black arm bands, brown pants, black shoes, and a padlock necklace.

In an Ultimate Alien flashback, 11-year-old looked the same as in the original series, but had jeans instead of cargo pants.

In Omniverse flashbacks, 12-year-old Kevin looked the same as before except for his pants being colored grey and his padlock necklace being marked with an "11".

In the first two seasons of Alien Force and most of Ultimate Alien, Kevin wore a black T-shirt over a grey long sleeved shirt, blue pants, and black shoes, and had his hair styled into a choppy mullet.

In season three of Alien Force, Kevin wore a white shirt, a blue short sleeved jacket, blue pants, and black shoes.

In Omniverse, 17-year-old Kevin wears a black shirt, a long sleeved grey shirt, and blue wholesters. He also wore a padlock necklace similar to the one he wore when he was 11, but marked with an "11".

Beginning in "Many Happy Returns", Kevin grew a few chin whiskers, and gained stripes on his gray shirt. In "Weapon XI: Part 2", Kevin gained a cross-shaped scar on his chin due to being whipped by Swampfire, which his counterpart in Ben 10,000's timeline also has.

In the 2016 reboot series, Kevin looks mostly the same as in the original series except that his eyes do not have marks around them, he does not have arm bands, and wears blue jeans, black shoes that are red at the bottom, and a brown Omnitrix-type device called the Antitrix on his left wrist.

Personality
When Kevin first appeared in the original series, he quickly became one of Ben Tennyson's most notable enemies. However, he reformed in Alien Force, and became one of the main heroes. In this continuity, he is an Osmosian capable of absorbing energy, matter, and DNA.

In the reboot, Kevin is a semi-antagonist introduced in season 3, being an enemy to Ben in certain episodes and an ally in others. In this continuity, he is an ordinary human equipped with a replica of the Omnitrix called the Antitrix that he generally uses to fight Ben out of pride and jealousy.

Mutations
Kevin as undergone multiple mutations, most of which involved using his powers on the Omnitrix.

Kevin 11
Kevin's first major mutation, dubbed "Kevin 11", occurs in the original series episode "Framed" when his powers got out of control. In a flashback featured in the Ultimate Alien episode "...Nor Iron Bars a Cage", Kevin was stuck in this form until a Null Void prisoner named Kwarrel taught him to control his anger and master his powers, resulting in Kevin reverting into human form.

This form mostly resembled a reddish-pink Tetramand but with an upper left arm resembling a Pyronite's, an upper right arm similar to that of a Petrosapien, and lower arms resembling that of a Vulpimancer.

Kevin 11 had Lepidopterran wings, a Kineceleran tail, an Ectonurite eye track on his chest, and an upper back resembling a Galvanic Mechamorph. His head consisted of Kevin's hair and ears, two left eyes similar to those of a Tetramand, a Galvan-like right eye, and the lure, teeth, and gills of a Piscciss Volann. He wore cargo pants in the original series, but switched into jeans prior to an Ultimate Alien flashback, according to Dwayne McDuffie.

Mutant Kevin (young)
Kevin's second major mutation occurs in a flashback in the Omniverse episode "Weapon XI: Part 2" when he uses his powers on the Omnitrix during a fight with Eye Guy. However, he is restored to normal after being knocked out by Argit before being taken back to the Null Void by the Amalgam Kids.

12-year-old Mutant Kevin's appearance was similar to, yet different, from Kevin 11. His face retained Kevin's structure and hair, but had green skin colored like a Florauna, a right eye similar to that of a Loboan, a left eye similar to that of an Opticoid, a mouth similar to that of a Gourmand, and a head fin and eyes on his chin similar to that of a To'kustar.

His body mostly resembled an Arburian Pelarota's, but with a Polar Manzardill's back and fins, a Splixson's lower chest and sensory nodes, Thep Khufan bandages, and Transylian shoulders. His arms had lower parts resembling an Arburian Pelarota's and upper parts resembling a Transylian's with red Opticoid eyes, Florauna-like spikes, and fingers resembling Florauna tentacles. He also had Splixson legs, Florauna eggplant bombs, and a Gourmand tail in a length similar to Wildvine's tentacles. He wore Kevin's pants and a Thep Khufan crown.

Mixed Material Kevin
Kevin's third major mutation occurs in the Alien Force episode, "Vengeance of Vilgax: Part 1", when Ben's attempt to hack the Omnitrix goes wrong, and the Omnitrix becomes overloaded, releasing a feedback that alters Kevin's DNA with those of various aliens in the Codon Stream. However, he was later turned back to normal in "The Final Battle: Part 2" when the Omnitrix was destroyed, due to the Omnitrix's energy having previously kept him in that form.

Unlike his other mutations, Kevin retained his original frame, and instead had his body made out of common elements. The right half of his face, the left half of his chest, the upper right half of his chest, part of his back, and his left arm were made of concrete, the lower right half of his chest, part of his back, his stomach, and his right arm were made of metal, the left half of his face was made of Taydenite, and his legs were made of wood.

Ultimate Kevin
Kevin's fourth major mutation occurs in the Ultimate Alien episode "The Forge of Creation" when he absorbs DNA from the Ultimatrix to stop Ultimate Aggregor from absorbing the powers of a newborn Celestialsapien. He easily drains Ultimate Aggregor's powers, reverting him back into his original form, and then left the Forge of Creation. However, he was later cured in "Absolute Power: Part 2" thanks to the efforts of Ben, Gwen, Cooper Daniels, and Darkstar.

Ultimate Kevin's composition was more complex than his earlier mutations from his youth. His face mostly resembled an Aerophibian's, but with Kevin's hair, a patch around the right eye resembling an Evolved Vaxasaurian, and a jaw similar to that of an Evolved Arachnichimp but with an interior resembling that of a Sonorosian. His torso resembled a Vaxasaurian's, but the backside was colored like an Aerophibian and had a set of Necrofriggian wings.

His right arm mostly resembled a Petrosapien's but with two Crystalsapien crystal spikes on his shoulder and a claw similar to that of a Biosovortian. His left arm mostly resembled a Methanosian's, but with a Biovosortian spike on his shoulder and an Appoplexian's wrist claw. He had an Aerophibian-like right foot and an Appoplexian-like left foot.

Ultimate Kevin also had a Vaxasaurian tail, two Cerebrocrustacean legs in place of a secondary left arm, a secondary right arm resembling an Arachnichimp's, and Orishan water ports.

Mutant Kevin (teenage)
Kevin's fifth major mutation occurs in the Omniverse episode "Weapon XI: Part 2", when he uses his powers on the Omnitrix during a fight with Gutrot. However, he willingly reverts to his human form after betraying Servantis and freeing the Amalgam Kids from his mind control.

17-year-old Mutant Kevin's face resembled that of a Gimlinopithecus, but with red eyes, Kevin's hair, a Vladat-like mouth, a crest resembling both a Gimlinopithecus and an Insectoid, and Conductoid antennae.

He had an upper right arm resembling a Segmentasapien's, an upper left arm resembling a Galilean's, a lower right arm resembling a Pturbosaurian's, and a lower left arm resembling an Atrocian's but with sharper claws. His torso mostly resembled a Gimlinopithecus's, with pieces of both Segmentasapien and Galilean near the shoulders.

He had a uneven set of wings, with the left wing resembling a Nemuina's and the right wing resembling a Pturbosaurian's, and Orthopterran legs. He wears pants resembling Kevin's Rooter uniform.

Monster Kevin
In the reboot episode "Which Watch", Kevin is turned into an amalgam of all 11 of his Antitrix aliens by Charmcaster in order to fight Ben and Gwen. However, he is returned to his original form after being tricked into using his Pyronite abilities to burn Charmcaster's spellbook beyond repair.

His head resembled Kevin's but a goatee resembling Quad Smack's, and a mane resembling Bashmouth's. He had purple skin, and a torso resembling Quad Smack's but with six arms rather than four.

His upper left arm resembled Crystalfist's, while his upper right arm was a purple version of Hot Shot's. His middle left arm resembled Thornblade's while his middle right arm was a purple version of Bootleg's. His lower left arm resembled Undertow's, while his lower right arm resembled Dark Matter's. He also had Wreckingbolt's back, purple versions of Skunkmoth's wings, and Rush's tail in place of legs.

Secondary Mutations
In "Kevin 11", Kevin absorbed some of Heatblast's DNA and temporarily became half-Pyronite, with his left arm and lower body remaining unaltered, and his upper right chest, head, right arm and shoulder resembling that of a Pyronite.

Later in the same episode, Kevin absorbed some of Four Arms' DNA and temporarily became half-Tetramand. While his hair and lower body's clothing remain unaltered, Kevin's skin turned red, he gained Tetramand eyes and crooked teeth, and his arms enlarged and gained black fingernails on each hand. He also had four holes on the sides of his shirt, allowing for four thin arms to extend through.