Mandy is perpetually a cynical, merciless girl from Endsville. She is the tritagonist of the show. Sometimes, she serves as a protagonist of the show. In stark contrast to her cheerful, talkative, uniquely stupid “friend” Billy, she is shown to be bitter, quiet, sensible, callous and intelligent.

After the theme song, Mandy is shown in front of a black screen, usually speaking to the viewers in a creepy, sarcastic way. This is similar to the couch gag opening of The Simpsons.