Animated Character Database

Kenneth "Ken" Tennyson is Ben and Kai's son and Gwendolyn's brother from an alternate timeline.


Regular Appearances[]

Ken bears a striking resemblance to his father when he was his age, albeit inheriting minimal features from his mother. His clothes are modeled after his father's. These include a white skin-tight T-shirt with black accents and borders at the sleeves, and his trademark baggy green cargo pants. Ken's eye color is even the same as Ben's. His skin tone is slightly tanned, his hair is dark brown in color without any strands hanging down the back like Ben's did at his age, and his nose slightly flatter and more straight compared to Ben's, traits which he inherited from Kai.

Occasional Appearances[]

Ken wears long-sleeved light blue pajamas.

Ken without the Omnitrix

Ken in his pajamas


Ken is very much like his father was when he was 10 years old, as exemplified by his immediate friendship with fellow troublemaker Devlin Levin.

Ken was shown to be slightly more intelligent and resourceful than his father was at the same age, as he used Grey Matter to hack his Omnitrix and remove the limiter, something that his father seemingly did not consider doing himself.


Ben 10[]

Ken first appeared in Ken 10, where he celebrated his 10th birthday. Among the gifts he received were a hoverboard from his great-grandfather, a Rock Monster pet from his aunt, and his own Omnitrix from his father. Ken, initially ecstatic about the Omnitrix, was soon disappointed with his pre-selection of aliens. Furthermore, even though Ken was allowed to join his father when he was alien hunting, Ben's years of experience and efficiency left Ken in the dust without any kicks.

Going out flying with the hoverboard, Ken ran into Devlin, a young street urchin who befriended him and consoled him about his issues with his father. Later that night, while his headquarters were being broken into, Ben initially decided to allow his son to join in against whatever foe has broken in this time, until he discovered the one responsible to be none other than his old foe Kevin Levin and grounded Ken to his room.

While the two fought, Ken used Grey Matter to sneak out of his room, eventually arriving in the empty Null Void Chamber just as Kevin fled. Meeting up with Devlin in the morning, he proposed that they try to deduce what was wrong with the Null Void Projector in order to prove themselves to Ben. Having deduced and located the projector, Ken and Devlin broke in, only for Devlin to reveal that he was the one who Ben was fighting.

Furthermore, he released his father, the real Kevin 11,000, who proceeded to beat on the newly arrived Ben, not caring about his son. Ken was able to use Grey Matter to crack the Omnitrix to remove the limiter and aided his father alongside Devlin to fight Kevin. Getting wounded in the crossfire, Ken's injury enraged Ben to the point that he beat Kevin into the ground. Devlin captured Kevin in a Null Void Containment Egg. With Kevin now in custody once more, Devlin came to live with Ben and Ken.

Powers and Abilities[]

  • Omnitrix



Ken wears an Omnitrix made by his father on his left wrist. Like Ben, Ken had access to only 10 alien forms at first. However, its playlist differed greatly than what Ben started out with. Wanting to make sure Ken wasn't in danger of hurting himself or anybody else like Ben was when he first got the Omnitrix, he took the liberty of downloading some of the least collateral aliens with only minimal battlefield use: Wildvine, Ditto, Buzzshock, Spitter, Snakepit, Sandbox, Shellhead, and Toepick. However, for the sake of having an escape plan, he did leave him with two of his own classics: XLR8 and Stinkfly. Ken convinced Ben to replace Toepick with Grey Matter, whom he later used to remove the limiter of his Omnitrix during his fight with Kevin 11,000.

Ken owns an X321 hoverboard, given to him by Max.


Ben 10[]

Season 4[]

  • Ken 10 (first appearance)


  • Ken's favorite Omnitrix aliens are Four Arms, Diamondhead, Way Big, and Atomix, the latter of which Ken seemed to be most excited to turn into than any other alien when he got his Omnitrix.
  • Ken's mother Kai missed his 10th birthday due to being on a diplomatic mission in the Shadow Realm.
  • Ken was designed by Thomas Perkins. Prior to his introduction, Thomas had a story in mind for how the tale of Ben Tennyson would eventually lead to a successor for the Omnitrix.
  • Thomas Perkins had always intended for a future version of Kai to be Ken's mother, even though it was not scripted at the time. This is likely because, during the Original Series, Kai was the only real crush Ben had as far as Perkins can recall.


  1. ↑ The Ben 10,000 from Omniverse is stated to be Ben Prime's true future self.It was also stated that the Ben 10,000 from Omniverse is the same character as the Ben 10,000 from the Original Series.However, the above two statements are inherently contradictory, because the Original Series Ben 10,000 was from an alternate timeline in which he never travelled to the future when he was 10, and consequently did not give Max a cake on his 60th birthday, while Ben Prime did. Thus, the Original Series Ben 10,000 did not recall the events of the episode.