We've all seen them, sneaking around in rock pools on the beach and walking sideways in an unsettling way. Yup, those crabs are evil and they're up to something, but you won't believe what! 

There's crabs picking fights with other animals AND with other crabs! There's crabs crushing objects with their claws. There's a whole island that gets taken over by crabs. And if you haven't yet seen what the giant coconut crab looks like, then get ready because it's terrifying!! You'll never look at a crab the same way again.