The Glaucus atlanticus sea slug—commonly known as the blue sea slug or blue dragon—is indeed a genuine species.Typically just an inch long,it frequently feeds on Portuguese man o’ wars.

A gas-filled sac in the stomach allows the small slug to float, and a muscular foot structure is used to cling to the surface. Then, if it floats by a man o’ war, the blue dragon locks onto the larger creature’s tentacles and consumes the toxic cells that the man o’ war uses to immobilize fish.The slug is immune to the toxins and collects them in special sacs within the finger-like branches at the end of its appendages—to deploy later on.

Because the venom is concentrated in the tiny fingers,blue dragons can have more powerful stings. Look but don’t touch.

More Info: www.smithsonianmag.com