When we think of slugs, we often picture slimy brown garden creatures. But under the sea, slugs truly come in every color of the rainbow!

Angelic, though, these creatures are not. Each sea slug has dozens of digits fanning out from their finlike appendages in gradients from gray-white to a flame-blue. And each of those cerata can ...

What exactly is this unusual blue sea creature? Get to know one of the more unusual members of the sea slug family in our quick look.

Each sea slug has dozens of digits fanning out from their finlike appendages in gradients from gray-white to a flame-blue. And each of those cerata can deliver a painful, sometimes dangerous, sting.

The sea slugs are only an inch long, but their primary food source is the highly venomous jellyfish species called the Portuguese man o' war. This means the blue sea dragons can inflict a sting ...