Bellicus

Bellicus is Alien X's voice of rage and aggression.

He first appeared in the episode X = Ben + 2 when Ben transformed into Alien X, and Ben quickly discovered he was locked inside the form because of the eternal debates between the two entities who control its body, Serena and Bellicus. He is the one who states that Ben is the voice of reason in this part of the transformation. Professor Paradox is not allowed to be closer than 500 light years to him and Serena, or any Celestialsapien for that matter.

Appearance
Bellicus looks like a male green human face with very realistic features (i.e. the wrinkles on his face). In Omniverse however, some of the features were taken out becasue of the new animation style.

Powers and Abilities
Bellicus, along with Serena (and by extension Ben), have the ability to warp reality.

Weaknesses
Due to Alien X not being able to do anything without a consensus from two of the three parts of its personality, Bellicus is relatively powerless on his own.

Bellicus can be terrifed by Toepick's face.

Alien Force

 * X = Ben + 2 (first appearance)

Ultimate Alien

 * The Forge of Creation (first re-appearance)
 * The Ultimate Enemy: Part 2 (flashback; cameo)

Omniverse

 * So Long, and Thanks for All the Smoothies (first re-appearance)

Ben 10 Alien Force: Vilgax Attacks
Ben got him and Serena to allow him to control Alien X before Vilgax took over the world.

Etymology
Bellicus' name seems to derived or based off "Belligerent" or "Bellicose", meaning very eager to fight, which describes much of Bellicus' personality.

Trivia

 * He seems to have a fondness of the dinosaurs, as he tried to persuade Ben into preventing their extinction in X = Ben + 2.
 * His tabled motion to save the dinosaurs was argument number 80 million and 3 (80,000,003).