The Head (1997)

Roughly-drawn but well-written cult cartoon about alien invasion. Small aliens on Earth, needing human receptacles, expand their hosts' craniums to ludicrous dimensions to use as living quarters. One such alien inhabits an average bloke's head during a mugging, giving him special powers to fight off his attackers. He explains that he's on the trail of an enemy from his planet, who's looking to take over the world. Not believed by anyone, and as a stand-out with his huge head, he teams up with a group of other freaks to save the world. They have to battle not just the alien, but the FBI agents also on the trail - and things aren't helped by his girlfriend, whose head is taken over too.