Benjamin Kirby Tennyson
When ten year old Ben Tennyson, his cousin Gwen, and their grandfather Max are on their summer camping trip, Ben finds an alien pod on the ground. When he examines it, he finds a mysterious, watch-like device called the Omnitrix. The device attaches itself permanently to his wrist and gives him the ability to transform into a variety of alien life-forms, each with its own unique powers. Although Ben soon realizes that he has a responsibility to help others with these new abilities at his disposal, he is not above a little super-powered mischief every now and then. Along with Gwen and Grandpa Max, Ben embarks on a summer-long adventure to fight evil, both extraterrestrial and earthly.
OmnitrixThe Omnitrix is the mysterious watch-like alien device that allows the user to transform into various alien forms by combining the DNA of the selected alien with the user's own DNA, effectively turning them into the alien species the user has selected. The alien form is selected by unlocking the control dial, turning the control dial to the desired alien species which is displayed on the Omnitrix's display, then pressing the control dial back into place completing the transformation. The alien DNA also seems to contain some aspects of the original aliens' personality; when questioned how it felt to be an alien, Ben described it as follows: "It kinda freaked me out at first. It was like I was me...but it was also like I was somebody else."
The Omnitrix was originally created by Azmuth (a Galvan like Greymatter) to allow the people of the universe a way to "walk in someone else's shoes". However, many beings saw the Omnitrix's abilities as something that could be used as a powerful weaponó,most prominently the villain Vilgax who claims it to be the most powerful weapon in the galaxy. Fearing that people might misuse the Omnitrix for this very reason, Azmuth put several safeguards in place to ensure that whoever used the Omnitrix would not have full access to its powers. Several of these safeguards include transforming into an alien different from the one that is selected on the control dial, the ten minute auto time-out, the restriction of only ten accessible aliens, and a self-destruct mechanism. However, these safeguards are disabled once the Master Control for the Omnitrix is unlocked, which is apparently done by a random combination of selections on the control dial. Once the Master Control is unlocked, the user can stay in their alien form indefinitely and is also able to switch between alien forms at will just by thinking about it, speaking the name its user has given any alien, or turning the badge with the Omnitrix insignia on it.
In addition to the aliens that were pre-programmed into the Omnitrix's DNA sequencer by Azmuth, the Omnitrix also possess the ability to absorb DNA samples from other alien species by simply coming into contact with them, effectively downloading a DNA sample and allowing access to that form.