Ditto

Ditto is a Splixson (based on the word 'split') from the Earth-like Planet Hathor (the name of an Egyptian goddess, who was often depicted as appearing in seven identical figures).

Powers and Abilities
Ditto is a small, humanoid alien with the ability to clone himself without limit. Every clone operates independently, regardless of whether or not the others wants them to, and each clone is indistinguishable from the others. Ditto is also no stronger or faster than his size suggests.

Weaknesses
All of the clones share a link with each other, making it so that when a clone is hurt, the other clones feel its pain. Also, if one clone is killed, the others are automatically killed as well, thus negating the ability to form an army of clones. If one of the clones is separated from the others by a great distance, then when the Omnitrix times out, the wearer will not transform back into normal, or be able to become another alien until all the clones are brought back into one. Ditto, while cloning, is vulnerable because when he clones opponent can attack them.

Original Series
Ditto made his debut in the episode Divided We Stand, where he fought Dr. Animo's mutant bird and was later caught to have his DNA copied. He was later used again to defeat Animo's Stinkfly replications. He was used again in Ready to Rumble, where he saved Porcupine and Gaterboy's mother. He was later used in the non-canon episode Ken 10 by Kenny Tennyson to find the Null Void with Devlin Levin.

Ben 10: Ultimate Alien

 * Ditto_UA.png Ultimatrix symbol has moved from his forehead to his chest.
 * The three bulbs on his chest are now grey.
 * Ditto was unlocked in Ben 10,000 Returns by Ben 10,000. He has yet to make an appearance.

Trivia

 * He seems to be an homage The warners, having a iconic voice actor, similar manerisms (closing their mouth with their touge sticking out, and streching for comidic effect) and similar color layout.
 * Ditto was the third (of five) of Ben's transformations to last for most of an episode due to his inability to change back. The first being Grey Matter, second being Benwolf, fourth being Alien X, and fifth being Rath.
 * Strangely, when Ben first unlocks Ditto, Grandpa Max doesn't stop Ben from using him on the beach completely exposed, where he is visible to the public.
 * Echo Echo proves to be a much more efficient choice than Ditto because he is the more enhanced version of a duplicating alien with it being more powerful and a handful to defeat.
 * Ditto's voice is that of Yakko's from the television series Animaniacs.
 * If the Omnitrix times out while Ditto is split into multiple clones, the Omnitrix will try to pull the clones together into one Ditto. If unsuccessful, it will not time out. It is unknown if the Ultimatrix will do this.
 * It seems that whenever Ben turns into Ditto, his sense of humor becomes greater and greater. This may just be because Ben is really happy to have more then one of himself.
 * Ditto is one of the three aliens to never have been in any kind of Ben 10 game, the other two being Benmummy and Benvicktor.
 * Ditto also is the name of a Pokémon that can transform itself into anything (Although, it needs to see the thing it's transforming into to copy it properly), except it is more of a blob like creature and this is not.
 * He is slightly more flexible than humans.
 * It is unknown right now what the bulbs on his arms are for, some people believe that it is a thing that shots a beam, a power that Ditto got when he got older.

Ben 10

 * Divided We Stand (x3 (first appearence (first transformation was accidental; selected alien was Stinkfly)
 * Ready to Rumble
 * Ken 10 (used by Kenny)