Saw sharks and frilled sharks and ghost sharks, oh my! All sharks are pretty wild in one way or another—but these sharks might just be the wackiest of them all. With extendable jaws, poisonous flesh, and a dazzling array of adaptations ranging from glowing eyes to glowing underbellies, these sharks showcase the remarkable ways marine predators have evolved to survive in the ocean. Wonderful as they are, many of these sharks are threatened by accidental fishing and habitat destruction, which means there is a chance they will disappear before we even get to know them. Click on through for a weird, wacky, and wonderful ride!