The Brimstone Assembly is a fictional group of from the Venture Bros. show, specifically the episode A Very Venture Halloween. Both and characters from previous episodes belong to the Brimstone Assembly, as well as a number of unknown background characters. Once a year on Halloween, they commence in a "magic gathering" (a meeting or celebration like event, not to be confused with a similarly sounding card game). As of the time of A Very Venture Halloween, the group had met 331 times. This configurationof shapes is said to allow glimpses of the Netherworld and thus enhance magic cast inside it.