The Head: Saves the Earth(1995)

Finally, in his own animated feature! Jim (The Head) is a mutant super-hero with an insanely large cranium. A freak encounter left him with a problem. A big one: he's got an alien named Roy living inside his oversized dome. Plus, he's got the added headache of having to deal with an impending invasion of Earth by a fiendish army of evil parasitic aliens. Jim and Roy are feverishly assembling the Anti-Invasion Machine, whose five pieces have been scattered throughout the world. Will Jim and his skull-dwelling companion have the skill to save the Earth? Only the Head knows.