Alien Species
"It's Hero Time!"
―Ben's catchphrase.

Benjamin Kirby "Ben" Tennyson is a Human, cousin of Gwen Tennyson, and the grandson of veteran Plumber Max Tennyson and the Anodite Verdona.



Ben's physical appearance has changed from a 10 year old to a 16 year old. However, he retains brown hair, green eyes, pale skin, and is quite skinny for his age, though he shows a lot of muscle definition due to being athletic.


At the age of 10, he came in possession of the Omnitrix, a watch-like alien device containing genetic material from numerous different species, which allows him to temporarily transform into a number of alien forms. During this time he battled foes such as an Osmosian named Kevin Levin and the Chimera Sui Generis known as Vilgax.

About a year later, Ben became obsessed with a Conductoid named Feedback, though the form was destroyed by a mutant Galvanic Mechamorph named Malware. Sometime later, he took off the Omnitrix for an unknown reason.

Less than four years, Ben put back on the Omnitrix, which recalibrated and assumed a new form. However, he was forced to destroy the Omnitrix to prevent Vilgax from weaponizing it and obtained the Ultimatrix, an Omnitrix-type device with the ability to evolve his aliens into more powerful forms.

By age 16, Ben became world-famous and was given a second Omnitrix after Azmuth deemed him worthy of it; the one he had used prior was revealed to be a prototype.

Powers and abilities[]

Canon Omnitrix Aliens[]

Non-Canon Aliens[]

Theoretical Aliens[]

"Joke" Aliens[]

  • Brundlefoot
  • Crocduster
  • Dropsies
  • Mister Sister
  • Murphybed
  • Overround
  • Polywhirl
  • Port-A-Porty
  • Pyxl-Loaf
  • The Sledge
  • Splatterator
  • Tanker Bell
  • Tool Bucket
  • Tranquenstine
  • Turdberry
  • The Zilch



  1. Gax is exclusively available in the Reboot Continuity.
  2. Eon is exclusively available in the Race Against time Timeline.
  3. Decimus Prime is exclusively available in the Classic Continuity.
  4. 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 These aliens are exclusively available in the Ben 10,000 Timeline.
  5. Archfiendzarro is exclusively available in Benzarro's Timeline.
  6. The Darkness is exclusively available in Nega Ben's Timeline.
  7. Trunk Man is exclusively available in Dimension 23.
  8. This alien is exclusively available in the Gweniverse.