The monkey that lives inside you butthole. Many legends have been and rumors have been spread about the mysterious butt monkey and all of them are true. The butt monkey possess many powers including the ability to swing from dingleberries and smoke tons and tons of weed. He resides in everyone's butthole, but few know he's there because he only reveals himself twice a year, on St. Patrick's Day and September 23. Don't ask why he just does.
"Dude what the hell is a butt monkey?"
It's the monkey that lives in your butthole!!!!