Ass-clown
Ass-clown (Ass klowne)

A group of people or individuals that like to dress up as clowns and cause mischief with their bottoms. This is usually achieved by sneaking up to a person or an "Ass target" as they are called, and expel gas on the person when they least expect it.On some cases when there are multiple Ass-clowns in one area they try to gang up on one person. They do this by circling the target while slapping their asses, and gradually shuffling closer to prevent escaping.
Call the police, that man has been attacked by an Ass-clown!