Before Optimus Prime started his war of conquest, Sinnertwin was Cybertron's most well-known and talented puppeteer. His puppet shows were popular with beings from planets all over the galaxy ranging from little protoforms all the way to royalty. He now fights as a part of Megatron's quest for peace, in the hopes that he and his puppets can someday entertain the masses once again. Sinnertwin transforms into a Cybertronian orthrus. He carries a small pistol in robot mode and a Rocket Grenade-Launcher and Flame Cannon in beast mode. He combines with the other Terrorcons to form Abominus.