In Australia, there are spiders big enough to eat snakes.
20
Cymothoa exigua is a type of parasite that enters through fish's gills, eats their tongue, and then replaces it.
6
During World War 1, starving wolves amassed in such great numbers that Germans and Russians had a temporary cease fire to fight off the wolf attacks.
45
Blue whale arteries are large enough for humans to swim through and their hearts are the size of cars.
12
Some older/less efficient worker termites will develop 'backpacks' of toxic chemicals that explode when the termite is threatened. They are essentially used as suicide bombers when the colony is being attacked.
8
Squirrels will sometimes adopt orphaned baby squirrels that they’re related to.
12