10 Worst Things Eric Cartman Has Ever Done

We go back now to a more grounded sense of devilry, which is even more toxic in its believability as something Cartman would do. This full display of selfishness is the worst thing that Cartman has ever done to one of his friends - if you can even call Kyle that.

In the episode Tonsil Trouble, Eric is accidentally given a transfusion with someone that had HIV positive blood when getting his tonsils removed. Unfortunately, this means that he is now infected with the virus. When coming to school and telling everyone, Kyle can barely contain his laughter. He isn't happy that Eric is infected, but feels a sense of irony in how Cartman has finally received punishment for all his awful behaviour.

In response to this, calmly and rationally, Eric deliberately infects Kyle with HIV. It is an entirely twisted thing to do, and in another awful way, he sees himself as the victim. He believes that he was in the right to commit this horrendous deed and the rest of the episode sees him struggle to understand how what he did was wrong.

Although they end up finding a cure, in the end, this really could have been the end of Kyle and Cartman's relationship, and no one would have blamed Kyle.