Freaks of Nature : Self-Inflating Fish
A river otter hunts for fish in Tanzania, Africa. It spots a puffer fish swimming, and dives in after it. To defend itself, the puffer swallows water until it inflates itself like a beach ball. Once inflated, the otter can't hold onto it or eat it. Eventually, it releases the puffer back into the river. Not only did the puffer fish save its own life, but it saved the otter's as well. It has a poisonous gallbladder that would have killed the otter, had it eaten the fish.
