The peacock mantis shrimp is found in the warm waters of the Indian and Pacific Oceans and is arguably one of the most captivating creatures in the sea. The peacock mantis shrimp lives in the crevices of coral and rocks on the ocean floor. A territorial creature, it has been known to exhibit aggressive behavior toward intruders. This ferocious shrimp has club-like appendages that fold beneath its body, resembling a praying mantis. If you ever hear a noise in your tank, you will know what it is now.