Whale or shark?

The idea of a 15-ton, 40-foot fish might be a bit freaky, especially when that fish is a shark. But humans have nothing to fear from the biggest non-mammalian swimmer in the ocean. It's one of just a few shark species that, rather than chomping large prey with fierce fangs, use their gaping mouths to filter plankton and small sea life into their gullets. It's this gentle nature, and of course gargantuan size, that lends this not-so-monstrous sea monster its name: the whale shark.