Mantis shrimp are a roughly 4 inch (10cm) long family that use specially adapted spear and club appendages to kill or stun prey. There are two main types of mantis shrimp, spearers and smashers.

The spearers primarily target fish, and snag their prey with jagged claws much like the preying mantis. They are powerful enough to cause painful injuries when handled improperly, and have been nicknamed "thumb splitters" by some.

The smasher variety will prey on hard shelled creatures such as crabs and shellfish. They crack the shells with their clubs and use a less powerful version of the spear afterward. Some of the smashers can produce up to 1500 newtons of force, enough to crack aquarium glass!