South American Leaf Fish (Monocirrhus polyacanthus)
An incredibly-adapted species, this fish is camouflaged to mimic a dead leaf, both in body shape and pattern. It can change colour to match its surroundings and has a projection from its bottom lip that resembles a leaf stalk. When hunting, it stalks its prey in a head-down stance, appearing to drift towards it like a dead leaf drifting in a current. When it strikes at an item of prey the entire mouth protrudes outwards, forming a large tube into which the prey is sucked, usually head first. This happens so quickly it is often difficult to see. It can swallow prey almost as big as itself in this way.
Image source
(via thearidee)
