Mutants are basically dumb brutes, and Carcass is no different. Horrific and hostile, even for a Lunartix, he destroys everything and everyone in his path.
Devil's Due G.I. Joe vs. the Transformers comics continuity
Carcass and Predacon were recruited by Lobotomaxx to help pillage the backwater planet of Earth. Upon arriving in Earth's solar system, however, all three would-be raiders and their ship were devoured by Unicron.
Recruited into the army of thralls that guard Unicron's vast interior from invaders, Carcass battled Cosmos and Flint when they penetrated the chaos bringer's exterior. Grappling with Flint at Unicron's brain, Unicron spoke to the human through the alien, mocking his insignificance. Flint tossed a sack of metal-eating fungus at the monstrous servitor and detonated it with a blast from his shotgun, spreading the destructive contagion to Unicron himself. Carcass's fate in the resulting conflagration is unknown.
- According to his filecard, Carcass hails from the planet Mirtonia. Whether this is at all connected to the Mirtonian Constellation is unknown.