Ben 10,000 (Original)

Benjamin "Ben" Kirby Tennyson, nicknamed Ben 10,000, is the fully grown version of Ben, from a possible future.

Ben 10,000 has become a full-time hero. He is tall, more muscular, and sports a full-beard. The Omnitrix has also changed in appearance, becoming bulkier and more gauntlet-like in shape. He is recognized everywhere as Ben 10,000, no matter what alien form he is using (because his aliens have an Omnitrix symbol).

Ben 10,000's nickname comes from the fact that Ben now has access to at least 10,000 alien forms (though he says he stopped counting since then), he also has unlocked the Omnitrix's Master Control, allowing him to switch forms at will, without timing out.

Appearance
In Ben 10,000, Ben 10,000 had his hair slicked back, he sported a full beard, he has a muscular build to him, and he wore a white-striped black shirt with short sleeves, black fingerless gloves, green pants, and black boots.

In Ken 10, Ben 10,000's hair is more tousled, still sporting the beard, and his hair went gray at the back and sides of his head, he went back to wearing his original shirt black-striped, white shirt with short sleeves, green pants and black and white boots. In addition to wearing his classic look, he has a belt with pouches.

In Ben Again, Ben 10,000 has less gray hair on the sides and back of his head. His wardrobe has changed a bit; he now wears a green-striped white shirt with short sleeves. His belt buckle has the number 10K on it, colored green. He has kneepads on his knees.

Personality
Ben 10,000 had stayed cocky and happy until he was 15 when Vilgax showed up one day. It's unclear about what happened that day that caused him to change, but it caused him to mutilate Vilgax. Ever since then, Ben 10,000 became serious about the hero business. He stopped naming his aliens. He stayed this serious until he ran into his younger self. After taking on Vilgax, Ben 10,000 started to lighten up in time for his Grandpa's birthday.

After Animo's break in, it's shown that Ben 10,000 still has lightened up, and has been reflected in his clothing, the fact that he started naming his aliens again and his time with his son.

Despite his mature attitude, Ben 10,000 still has a teasing side after his lightening up years ago, calling the alternate counterpart of his cousin Gwen 10 "dweeb" when she made a smart quirk about him.

Ben 10
Having been fighting crime for such a long time, Ben 10,000 has grown into a strict and serious character, stopping naming his aliens (which the present Ben considers "half the fun" of using them), and has a darker way of dealing with villains, such as defeating Vilgax by literally mutilating him (according to a pop-up, this happened when Ben 10,000 was 15), though his cousin brought his and her younger selves to help Ben 10,000 get a major attitude adjustment. This interaction with his younger self caused him to lighten up somewhat, renaming his aliens. Ben's alien forms have aged with him, which is evident in their appearances and abilities. For example, Ben 10,000's XLR8 is noticeably taller with gray outlines in place of the ordinary blue, as well as being considerably faster.

It was shown that Ben 10,000 has a son named Kenny (after Ben's cousin Ken) and a daughter named Gwendolyn (named after his cousin Gwen). On Kenny's tenth birthday he gives him an Omnitrix like the one he had in the original series (like his first one, only he has 10 accessible aliens and has the Master Control locked.) The aliens he gave Ken were Spitter, Buzzshock, Shellhead, Ditto, Wildvine, Stinkfly, Toepick, XLR8, Sandbox and Snakepit. However, Toepick was later exchanged for Grey Matter because Kenny said that Toepick grosses him out.

Ultimate Alien
Ben 10,000 was mentioned by the other Ben 10,000 in Ben 10,000 Returns when Professor Paradox mentioned that they traveled into crosstime.

Omniverse
In Ben Again, Ben 10,000 came to Ben's time zone looking for Professor Paradox, asking the present Ben for Paradox's location. He also informed his younger self that "the Chronosapiens had gone rogue and Maltruant's temporal beasts are on a cross-dimensional rampage", he also states "this time war is getting out of hand."

In And Then There Were None, Ben 10,000 arrives along with Gwen 10 and Ben 23 to assist in the battle against the evil Bens in courtesy of Professor Paradox. Ben displays his first use of the Biomnitrix's fusion abilities to transform into Fourmungousaur. He fought Mad Ben (in the form of Rath) until he was annihilated by the Chronosapien Time Bomb. Ben 10,000 tried to stop the bomb by using his second fusion alien, Atomic-X but was erased immediately from existence, just like the other Bens.

In And Then There Was Ben, Ben 10,000 was visited by Professor Paradox and the other alternate Bens to be recruited for the ultimate battle against Vilgax and later on he was brought back into existence by No Watch Ben as Clockwork. Ben 10,000 and his fellow Bens battled Vilgax together and won. He was then sent back to his own timeline along with all other Bens.

In Fight at the Museum, Ben hugged his beloved wife after she received her orb back.

Ben 10

 * Ben 10,000 (first appearance)
 * Ken 10

Ben 10: Omniverse

 * Ben Again (first re-appearance)
 * And Then There Were None
 * And Then There Was Ben
 * Fight at the Museum (cameo)

Trivia

 * Ben 10,000 appears to favor XLR8 over any other aliens.
 * The enhanced version of the episode Ben 10,000 reveals that the events that happened when Ben 10,000 was 15 are what caused him to lose his joy of being a hero.
 * In the Pop-Up version of Ken 10, Ben 10,000 and Kai married and had two children.
 * Though Derrick has confirmed in Omniverse Ben only has Ken.
 * According to Derrick J. Wyatt, the reason the original Ben 10,000 came back was because, according to him, Ultimate Ben 10,000 was a really lame idea.