Many species of starfish feed by ejecting their stomachs out through their mouths.

Because of this ability, a starfish (or sea star) is not limited to hunting prey that are smaller than the size of its mouth. Therefore, many animals such as clams and oysters serve as otherwise unexpected targets for these sneaky hunters. The starfish pries open the mollusk’s shell using its suction-cupped feet and slips its stomach inside the opening. The stomach then begins digesting its helpless quarry OUTSIDE the starfish’s body until retracting into the sea star’s mouth to finish the job.

You can watch the stomach expand and retract in this bizarre video!