Eric Cartman

Eric Cartman, the "fat kid" in the popular animated series South Park, is a self-centered, mean-spirited 9 year old child. Eric Cartman has a dark personality which often hints towards some sort of mental problems that he may be experiencing. He also seems to take pleasure from the sadness, misfortune of others and never really shows empathy. However, Cartman does not see himself as a bad guy because of the severity of his narcissism. It also seems like Cartman is motivated to be superior to the people around him, if only to then gloat about it in their faces.

Cartman is what you could describe as a natural leader, in the Machiavellian sense. He possesses skills that help him gain control of people and turn them against each other. He utilizes his public speaking skills to easily gain control of large groups because he is aware of how to take advantage of mob mentality and he uses these skills to achieve truly selfish and diabolical ends.
 
The only friend that Cartman seems to have is his stuffed frog, Clyde. Most of the characters within the series tolerate his presence at best as a nuisance and at worst as a diabolical menace. He usually associates himself with Kenny, Kyle, and Stan, mostly because they have put up with him so long that they are used to his extreme personality quirks. He holds a particularly strong hatred towards Kyle mainly on account of  his Jewish ancestry. This has led to many altercations between the two, involving fist-fights, scheming back and forth to undermine the other, and public humiliation. Cartman has lost most of the fights between the two, with the exception being a bet regarding Leprechauns' existence. Kyle lost the bet, but wouldn't suck Cartman's balls, which was the agreed upon arrangement. Instead, Cartman imagined Kyle doing the act in Imagination land, much to Kyle's dismay.
 
Eric's "father" is Liane Cartman, a promiscuous and wholly amoral hermaphrodite. It has not been revealed since the series inception who Cartman's mother is, although up until the episode entitled Cartman's Mom is Still a Dirty Slut, it was assumed that Liane Cartman was his mother until she revealed that she was a hermaphrodite, and therefore, unable to have children.