Murray Douglas Foster is a Canadian musician, vocalist, songwriter, director, playwright, screenwriter, and environmentalist. He is best known for his work as electric and upright bassist in the Canadian bands Moxy Früvous and Great Big Sea. In 2014, he directed the independent film, The Cocksure Lads Movie. He and Mike Ford also perform in live performance as a 1960s British Invasion styled band, The Cocksure Lads.