You mentioned Living Floors, maybe something like the Assassin's hood. A pod or small creature that drops on the targets head and sticks over it. Either growing to envelop them, or somehow swallowing them up into it. It could even be a sort of symbiote to another monster, with the hood blinding them while the real predator sneaks up.<br/><br/>I also had a thought of a giant catipillar or centipede type thing, that can only be killed from a spot ontop. Which means they have to climb on it and get to the spot. The catch is that it's covered with pores or something which act as mouths, and a wrong step will result in getting sucked down into it's body.