#3 Pufferfish
Few fish are more adorable than a chubby, portly pufferfish, but don’t be fooled by that! The pufferfish is the world’s second-most toxic vertebrate. Its toxin, which has no cure, kills by paralyzing the diaphragm and suffocating the victim.
Tetrodotoxin, a chemical that gives pufferfish their foul taste (and occasionally makes them lethal to other fish), is present in almost all of them. When compared to cyanide, tetrodotoxin is up to 1,200 times more deadly. 30 adults could be killed by the venom found in only one pufferfish.
In spite of this, it’s regarded as a delicacy in Japan, and only extremely competent chefs are allowed to prepare it; still, deaths continue to occur yearly.