Mercer is one of the Renegades, a black-ops squad of paroled prisoners assembled by Sgt. Slaughter and first appearing in G.I. Joe: The Movie (1987). First released as a Hasbro carded action figure in 1987.
Mercer appears in 2 episode synopses across the Sunbow (1983 to 1987) and DiC (1989 to 1992) runs, first appearing in DiC's "The Eliminator" (1991). Full screencap and continuity review pending.