16. Humboldt Squid

Sailors used to fear giant squid, but the real terror of the sea is a fair bit smaller. Meet the Humboldt squid, aka the “red devil” on account of the sinister red color it flashes when it’s exited or angry. They attack prey – including humans – in packs of up to 1,200 individuals. The worst is their beak, which diver Scott Cassell told the Telegraph can “mechanically amputate your hand.”