Sullivan's Ass (or Butt) was a popular gag in Nova and Sp00n's community. It was slowly becoming an internet meme, until the Dead Rising 2 let's play ended. Sullivan's Ass also appeared in Dead Rising 2: Off The Record and in Nonsensical Saints Row: The Third, with the gas (Sullivan's farts contained in canisters) as revealed in Episode 48.
When the two were doing their Dead Rising 2 playthrough, they joked around about Sullivan, a main character in the game's, ass, similar to Nova's Talking Butt. During the playthrough, 'mutant zombies' were made by a gas. The two joked that it was Sullivan's 'poop stink'. In Dead Rising 3, Sullivan made a return when Sp00n was making a joke about Sullivan having a dirty ass.