Ssserpent

Ssserpent is a villain in Ben 10: Alien Force and Ben 10: Ultimate Alien. He referred himself as "The Snake that Walks Like a Man" (although he doesn't have any feet to be able to walk; he slithers, he just does it upright).

Appearance
He resembles a snake that stands as tall as human. He has two arms that end in snake mouth's. His arms are also bone- and joint-less allowing him a vast amount of flexibility.

Alien Force
Ssserpent first appeared in Vengeance of Vilgax: Part 1. He proved to be tough for even Gwen and Kevin only to be easily defeated by the arrival of Ben as Cannonbolt.

Ultimate Alien
Ssserpent returned in Video Games as the secondary villain. Having been paroled out of the Null Void Prison, he tries to fight Ben only to be crushed by two cars that Four Arms used as weapons. Ssserpent also reveals he wants to eat Ben as he said "You will be my evening snack." This may mean Ssserpent may be able to unhinge his jaws like a real snake.

Ssserpent makes his second appearance in Ultimate Alien in the episode The Perfect Girlfriend, where this time he is a much bigger threat. Apparently he has learned more and has been watching Ben allowing him to plan for Ben to use Goop. He was able to defeat Goop by trapping him in a machine, planning to separate Goop into the different components. However, when the police showed up he ran for it. Later, it appears that he can shed his skin like a real snake and it is unknown where he is now.

Powers and Abilities
Ssserpent is able to strangle his opponents' body like an Anaconda and also bite others. He can spit an acidic liquid, which was able to corrode metal.

Ben 10: Alien Force

 * Vengeance of Vilgax: Part 1 (first appearance)

Ben 10: Ultimate Alien

 * Video Games (first re-appearance)
 * The Perfect Girlfriend

Trivia

 * Ssserpent said that he'd been studying Ben's thinking actions in order to beat him which would have happened if "Julie" hadn't intervened.
 * It is confirmed by Dwayne McDuffie that his name is "Ssserpent" (with three S's, not one).
 * Sometimes when Ssserpent says something that has an S, the S is tripled (sss).
 * He is similar to a Nāga (snake man) in many ways.