Dunkleosteus

Though it looked like a squished (though terrifying) sardine, Dunkleosteus holds the record for the strongest bite of any animal, living or extinct. Able to fit a human in its mouth with one chomp, this bizarre prehistoric creature ruled the seas for 20 million years, leaving destruction in its wake. A pure carnivore, Dunkleosteus could weigh as much as an elephant and reach up to 33 feet (10 m) in length.