The Michigan Monster Mash happens once a year on Halloween night. It is a event where many people at a Halloween party get together in costumes and have a mass orgy. The best part of the Michigan Monster Mash is that everyone is in a costumes and no one knows who is who. So next Halloween go to a local part and do the mash ;)
The Michigan Monster Mash happened in Ann Arbor Michigan on Halloween night in 1999, and has happened ever year since.
by DR124 September 18, 2011