Life in the wild is all about the survival of the fittest, and some of nature’s beasts pack deadly abilities to ensure they are always the victor and never the victim.
Blue Ring Octopus

The blue ring octopus may be small and cute looking, but it is one of the most venomous species whose toxins can easily kill a grown man in no time. This octopus uses the same toxin, tetrodotoxin, for its self-defense as the puffer fish.
It packs another fatal one only for hunting. This other toxin is harmless to humans, but tetrodotoxin is so strong a single dose in can knock down 26 humans at the same time.