Wellwater Conspiracy was an American rock band that formed in Seattle, Washington in 1993. The band was created by members of the grunge-era side project Hater. Wellwater Conspiracy featured Soundgarden drummer Matt Cameron and ex-Monster Magnet guitarist John McBain. The band originally featured Soundgarden bassist Ben Shepherd, who left the band in 1998. Various other artists have contributed to the band's albums, notably Queens of the Stone Age front man Josh Homme, Pearl Jam singer Eddie Vedder, and Soundgarden guitarist Kim Thayil.