A two headed serpent would be pretty cool - it could finally be a way to obtain a Fire/Water dual type Pokémon without it being weird lol. Or maybe you could even customise the types of its heads? I can see a lot of potential for something like this!
What do you guys think a Dark type snake Pokémon could look like? Honestly I'm really surprised one doesn't exist yet (unless I'm being really dumb and forgetting one!) since snakes are naturally quite stealthy/sneaky creatures, so what better animal to turn into a Dark type?