Swollen Members are a Canadian hip hop group from Vancouver, British Columbia, Canada consisting mainly of the duo Mad Child, and Prevail. They have been called "two of the most innovative people in hip-hop". Frequent collaborators include vocalist Moka Only (who was actually a member of the group for a short period of time in the 90s, and then again from 2002–2005) and producer Rob The Viking, an official group member since 2002. Since the group's formation in 1994, Swollen Members has released five studio albums, one Greatest hits album and one compilation, as well as numerous other singles.