Kevin Levin

Kevin Ethan Levin is an Osmosian and a member of Ben Tennyson's Team. When Kevin first appeared in the original series, he quickly became one of Ben's most notable enemies. However, he reformed in Alien Force, and became one of the main heroes until his departure, along with Gwen Tennyson in The More Things Change: Part 1.

Appearance
In the original series, Kevin was a thin and scrawny boy with shoulder-length black hair, pale skin and dark brown eyes with black-discolored marks around them. He wore a torn black T-shirt, black studded arm bands, brown cargo pants, black knee-length shoes, and a padlock necklace which is a spoil from his first crime: stealing a bike and using it to run away to New York. After absorbing the Omnitrix's feedback, Kevin was able to transform into exact copies of all of the unlocked aliens, missing an Omnitrix symbol. After the energy overwhelmed Kevin, he mutated into Kevin 11, a mixture of body parts from the 10 said aliens which completely destroyed his clothes, except for his cargo pants.

In Alien Force, Kevin grew into a tall and muscular young man. His eyes lacked the black marks (as his body fully recovered from and stopped absorbing energy). His normal attire was a tight black T-shirt over a grey long sleeve shirt, blue pants, and black combat shoes. His hair, although still long, was styled into a choppy mullet.

In Season 3 of Alien Force, he was seen wearing a short sleeved light blue jacket over a white muscular shirt, blue pants, and his black combat shoes. After he went through a second mutation, an unbalanced mixture of various matters, the transformation completely destroyed his clothes, except his briefs. As a result, Kevin had to wear an ID Mask in order to appear human. In his second mutation, he looked like a mixture of solid materials such as stone, wood, Taydenite, and metal.

In Ultimate Alien, he appeared exactly as he did in the first two seasons of Alien Force. During Kevin's time as Ultimate Kevin, his appearance was again an unbalanced mixture of various aliens that were currently accessible to Ben through his Ultimatrix.

In the first season of Omniverse, Kevin wore the same black shirt but the sleeves and collar were roughly cut, the sleeves on his long sleeved grey shirt were slightly torn and he wore blue wholesters. His hair was longer and straighter. His pants had a small tear below the left knee. He also wore a padlock necklace similar to the one he wore when he was 11, but marked with an "11". He also sported black discolored marks around his eyes, making him appear tired; these marks bore similarity to when he was 11 and still absorbing energy.

For the rest of the series, Kevin grows a few chin whiskers and his grey shirt gains stripes. In Weapon XI: Part 2, Kevin gets the same cross-shaped scar to his chin that future Kevin has.

12 year old Kevin in Omniverse looks exactly the same as how he does in the original series, except for the fact that the color of his cargo pants are grey instead of brown and his padlock necklace is marked with an "11".

Personality
Due to his complicated childhood and abilities, as a child, Kevin exhibited sociopathic tendencies, such as attempting to derail a money train, even though it'd kill countless passengers on another train. Kevin had an extremely negative outlook on life because of his countless hardships and struggles, feeling insecure about himself as well as having an incredibly low self-esteem. He had a deep-rooted hatred for other people and society in general. He was paranoid to the point of considering everyone to be his enemy because, as he put it, "Nobody's innocent! They just haven't had the chance to make fun of me yet!".