The Mata mata (Chelus fimbriata)

The appearance of the mata mata's shell resembles a piece of bark, and its head resembles fallen leaves.[16] As it remains motionless in the water, its skin flaps enable it to blend into the surrounding vegetation until a fish comes close.[16] The mata mata thrusts out its head and opens its large mouth as wide as possible, creating a low-pressure vacuum that sucks the prey into its mouth, known as suction feeding.[16] The mata mata snaps its mouth shut, the water is slowly expelled, and the fish is swallowed whole; the mata mata cannot chew due to the way its mouth is constructed.