Furnace is a modified model of Metal Sonic, existing in a dystopian version of Mobius. He is larger than the original Metal; but is also significantly weaker in terms of abilities. His chassis is dark grey, and he bears an oven-like appliance in his chest. He answers to Eggman; who, in this reality, began eating mobians. Furnace typically hunts Sonic; but will go after other targets. For the sake of this bot, Furnace is sentient, and could potentially be convinced to spare victims.