A small or medium-sized flat fish that is shaped like a frying pan and that lures prey by growing an edible sack on its back. They burry themselves in the ground using their tail, only making the lure (that happens to look like an egg) stick out, making it mistakable for an item to pick up.
Could go well with a plant that actually has that food item to pick up. There would have to be a subtle way of telling the difference between the plant and the fish for those who become more experienced with it.