:  The Porcupinefishes
Taxonomy: Tetraodontiformes, Porcupinefishes  (Diodontidae)
General Information: There are 6 general which include about 19 species of porcupinefishes. These fish have have obvious thick spines that cover the body. Most species have spines that lay flat except when the body is inflated. Their teeth are fused, making them capable of crushing prey.
Diet: They crush and eat sea urchins, sea stars, hermit crabs, crabs, snails, and many other hard-shelled invertebrates.
Final Note: The porcupinefishes contain a highly potent nerve toxin called tetrodotoxin. This toxin can kill humans or other animals if it were ingested. These fish are vulnerable to ich and other external parasites, and are even reported to carry a higher-than-normal number of intestinal worm parasites. The eggs of this group of fish are pelagic and float over large distances, dispersing them around the globe.

Examples at SeaScape Studio:
Porcupine Horned Puffer
Porcupine Pufferfish
Spiny Puffer