Mantis Shrimp

(Image credit: Jenny/Wikimedia Commons)The colorful mantis shrimp Gonodactylus smithii. Researchers compare mantis shrimp to "heavily armored caterpillars."

Peacock Mantis Shrimp

(Image credit: S. Baron)The peacock mantis shrimp Odontodactylus scyllarus from the Indo-Pacific boasts strong, hammer-like claws.

Peacock Mantis

(Image credit: Chris K Horne, Shutterstock)Peacock mantis shrimp are solitary hunters, capable of swinging their claws with a force equal to a .22 caliber bullet.

Mantis Shrimp with Eggs

(Image credit: scubaluna, Shutterstock)A mantis shrimp guards a raft of pink eggs.

Green Shrimp

(Image credit: Dray van Beeck, Shutterstock)Peacock mantis shrimp are known for their complex visual system.

Territorial Crustacean

(Image credit: Stubblefield Photography, < ahref="Stubblefield Photography">Shutterstock)Peacock mantis shrimp are highly territorial.

Armored Crustacean

(Image credit: < ahref="http://www.shutterstock.com/gallery-286909p1.html"> Olgysha, Shutterstock)A view of the colorful peacock mantis shrimp body.

Smashing Close-Up

(Image credit: Teguh Tirtaputra, Shutterstock)Peacock mantis shrimp are not shrimp, but their shrimp-like appearance (and tendency to attack like a praying mantis) gave them their name.