The Game Master has a lot of power to make this game fun. Every player except the Game Master plays for one head of a sizable monster - you can be a chimaera, a multi-headed dragon or something else. This brings three main conflicts - the obvious one with people not wanting you around, one of "How do I feed my huge body?" and the third of how your heads go along. It's better to cooperatively draw yourself first to get on the same page. If you're healthy and not starving, every head gets 3d6 for a scene, representing energy. Wounded heads get less (unconscious or dead zero) and while starving, every head gets less. You can use them to move your body around and actually do stuff, be it combat, searching for food or just trying to go somewhere. To do it, you roll any number of those dice. The Game Master sets target sum numbers for actual situations, giving bonuses freely for actions that make sense and directly subtracting rolls if multiple heads try to do a mutually incompatible actions. Keep in mind that heads might have different personalities. Try different settings (multi-core supercomputer?).
This was made with two main ideas. One, to subvert the standard “heroes go fighting monsters” in the way of Be the Wumpus. Second, partly inspired by Pokémon, comes from “how do heads of a monster get along?”