Mercer is a fictional character from the G.I. Joe: A Real American Hero toyline, comic books and animated series. He is a member of the G.I. Joe Team as one of Sgt. Slaughter's Renegades and debuted in 1987.

Sgt. Slaughter is a fictional character from the G.I. Joe: A Real American Hero toyline series. G.I. Joe used the persona of the American professional wrestler Robert Rudolph Remus, known in-character as Sgt. Slaughter, as a model for their character. Four versions of his action figure were released in the 1980s. Sgt. Slaughter's G.I. Joe version makes no reference to its professional wrestling inspiration, although the character does use wrestling moves. Remus also did the voice for the animated character, and appeared in person for introductions to the episodes that were originally G.I. Joe: The Movie. He was also the spokesman for the G.I. Joe toys from 1989 to early 1990, introducing the new vehicles and figures in commercials.