Deathbringer

The Deathbringer is a bio-mech bred by unknown parties to endure and fight in the most cruel of environments.

Fiction
The Deathbringer commanded the Reapers, a diverse group of alien "bogeymen" who sought to end all war in the universe by eliminating everything worth warring over. The Deathbringer extended an invitation to Sixshot to join their group, though Sixshot declined as he could not sever all sentimental attachments to the Decepticons. The Deathbringer took the rejection in stride, declaring that Sixshot would cross paths with the Reapers again some day, and perhaps then, he would be ready to join.

When Sixshot was called to Earth, the Reapers followed and launched an assault on the Decepticon base. the Deathbringer again made his pitch to Sixshot, helped by Starscream deliberately baiting the Decepticon, but the instant Sixshot signed on for the Reapers, Starscream deactivated him. Following that, the Deathbringer was attacked by Galvatron and infected with death itself, turning him into a shuffling horror that spread death and decay among the other Reapers by touch before he finally collapsed. The Deathbringer, his brethren, and their dream of ending war all became casualties of Nemesis Prime's ambitions.