Ultimate Ben

Ultimate Ben is the evolved form of Ben. His appearance does not change, despite evolving, but it enables Ben to use any alien's powers without needing to change his physical appearance.

Abilities
While in this form, Ben would just pronounce the name of any alien he choses to transform to (though it is not necessary) and press the Ultimatrix symbol on his chest. While Ben's human appearance does not change, it changes depending on the size of his chosen alien, as seen where he accessed Ultimate Humongousaur's powers, where his body frame increased to fit the form.

Aside from his main powers, Ultimate Ben also has access to his magical and Anodite powers, though he says this is from spending 20 years with one. The possibility that he knows more than he lets on may mean that Ultimate Ben has more abilities than his aliens from the Ultimatrix.

Aliens Accesed as Ultimate Ben

 * Ultimate Humongousaur X2
 * Articguana
 * Heatblast
 * Clockwork X2
 * Spidermonkey
 * Jetray
 * XLR8 X2
 * Diamondhead X2

Trivia

 * Because this form is linked heavily to the Ultimatrix, it is unknown if this form is the Ultimate Human form.
 * Ben says that he hasn't transformed into another alien for years since he discovered his Ultimate Ben form, the others having become unneeded since he can use all of their abilities from this single form.
 * The abilities he attained while in his Ultimate Human form to gain abilities without changing refers to human adaptability, as it is said to be a ability that excels all abilities of all species. http://dwaynemcduffie.com.lamphost.net/forums/viewtopic.php?f=2&t=314&p=3063&hilit=adaptability#p3063
 * Ben 10,000 refers to how it is his "best transformation."
 * Ben 10,000 said that young Ben will figure out all of his Ultimate Human abilities someday.
 * It was seen briefly in the episode Fame, after Ben reverted back from Spidermonkey, that Ben's eyes glowed pink for a moment. Dwayne McDuffie has hinted that the pink eyes Ben displayed after transforming back from his first time transforming into Ultimate Spidermonkey are part of the human ultimate form.
 * Since Ben states he can use all of his alien's abilities from this form, it is implied that he could use Alien X's abilities as well. Weather or not Ben would still have to deal with the other two personalities is unknown.