Swollen Members are a Canadian hip hop group from Vancouver, British Columbia, Canada consisting principally 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 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.