Bizarre creatures are floating around in our oceans-squishy, slimy, spiky-headed monsters. And they're not even grown up yet! These kids have to go through some drastic changes before they get to be adults.

Everyone knows that caterpillars and tadpoles go through metamorphosis, but so do some of the most monstrous creatures under the sea.

Take the spiky-headed zoea, somersaulting through the water on her way to becoming a blue crab. Or the gnathiid larva that sucks the fluid right out of a fish's eyeball through his needle-like mouth. That is, until he's full enough to become an adult that doesn't eat anything. Or the moon jellyfish that starts off as a small, orange blob and eventually plants itself on the seafloor and produces not one but many adult jellyfish.

Dive deep with these little monsters of the ocean to follow along as they go through drastic changes on their way to growing up.