Seasons seven and eight of South Park are packed with creative Cartman costumes, so let's just get to it without me saying things to make an ass out of myself.
In "I'm a Little Bit Country", Cartman travels back in time to 1776 and visits our Forefathers.
In "Lil' Crime Stoppers", Cartman and the boys become detectives and are assigned to bust a meth lab.
In "South Park is Gay", Cartman and the boys get caught up in the metrosexual trend.
Christian Rock Cartman
In "Christian Rock Hard", Cartman, Butters and Token start the Christian rock band "Faith + 1".
In "Grey Dawn", Cartman plays goalie when the boys have a street hockey game.
In "Grey Dawn", Cartman disguises himself as a black person to save the town from crazy senior citizens (and get rid of Kyle).
In "Casa Bonita", Cartman pretends to be a cannibal to trick Butters into hiding.
In "Good Times with Weapons", Cartman and the boys pretend to be ninjas.
In "AWESOM-O", Cartman plays a prank on Butters by pretending to be a robot.
Mentally Handicapped Cartman
In "Up the Down Steroid", Cartman pretends to be mentally handicapped to compete in The Special Olympics.
In "The Passion of the Jew", Cartman once again dresses up as Hitler after he is inspired by Mel Gibson's film "The Passion of the Christ".
In "Quest for Ratings", Cartman becomes a news anchor named "Rick Cartman" and exposes cough medicine abuse in schools.
In "Stupid Spoiled Whore Video Playset", Cartman tries to dress cool after he isn't invited to a party.
In "Cartman's Incredible Gift", Cartman believes he can fly and jumps off the roof of his house.
In "Cartman's Incredible Gift", Cartman jumps off the roof and believes his injury gives him psychic powers.