For every figure that made it into the line, dozens were proposed as concepts and sketches. Here’s a color marker comp (ink on a photocopy of pencil art) by Kurt Groen of an unproduced Cobra soldier — likely some kind of Viper — from spring of 1990. I’m not sure if this character made it into three dimensions, but I doubt it. Click for a slightly larger image:
Subtly refining the art and adding a touch of detail, Groen redrew this as a finished color presentation “painting,” but by the time he was involved with the brand the toy development process dictated the internal presentation paintings no longer be painted. The final art, not pictured, looks just about the same as the rough, above.
Presumably this character was initially pitched for the 1992 product line.