Shock is the green-skinned, twisted, skeletal, evil reindeer who wears a metal harness and rides the skeletal horses of the nightmare sleigh. He is one of the lead reindeer in the sleigh, and is the right-hand reindeer to the evil Santa Claus, Jack Skellington. Shock is a loyal servant to Jack Skellington, and serves as a commander and overseer of the reindeer team that pulls the Nightmare Sleigh.