Moon Colony Bloodbath is an EP released by the Mountain Goats and John Vanderslice while on tour in 2009.

John Darnielle had this to say about its status as a concept album: "Some of the songs have something to do with a loose rock opera/'concept album' idea about organ harvesting colonies on the moon and the employees thereof, who spent their off months living in secluded opulence in remote American locations.

Concepts like this are actually more fun when you abandon them but leave their traces kicking around, so that’s what we did.”[1] Bobby Beausoleil, who is serving a life sentence for murder and has association with the Manson Family, is the subject of lyrics on the track "Scorpio Rising".

The EP was initially produced in a limited vinyl run of 1,000 and sold during their "Gone Primitive" tour.

It starts with a gorgeously melancholy song with the lyric 'Let me die surrounded by machines,' and ends with the singer left alive after the Satanic massacre on the Moon, wearing a suit that keeps him warm but starving.