Born Spencer Linn, Mossback is an emcee and producer from Portland, OR. He is one half of the group Grim Salvo and one third of the production team ³³marrow.
Mossback, along with fellow Grim Salvo member, Sleuth, also release music as part of the progressive metal band The Odious.
He also has the account VYRGYN which is a metal (solo, I think) one, and he was the vocalist of the bands Great Regular Flavor and Mystrionics.