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).
His nickname comes from the fact that now Ben has access to at least 10,000 alien forms (he says he stopped counting), he also has unlocked the Omnitrix's Master Control, allowing Ben 10,000 to switch forms at will, without timing out.
He had stayed cocky and happy until he was 15 when Vilgax showed up one day. It's unclear about what happened that day caused him to change, but it caused him mutilate Vilgax. Ever since then, Ben 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 and his time with his son.
When he first appeared, 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, his hair is more tousled, still sporting the beard, and his hair went gray at the back and sides of his head, he went back 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 for various missions.
In Ben Again, he 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 in green. He has kneepads on his knees, and instead of having one Omnitrix on his left arm, he has the Biomnitrix on his arms.
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(after 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.
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 informed his younger self that the Chronosapiens had gone rogue and Maltruence's temporal beasts were on a interdimensional rampage and that this time war is getting out of hand.
Ben 10: Omniverse
- Ben Again (first re-appearance)
- Four Arms
- Way Big
- Ben 10,000 appears to favour 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.