At maturity Glaucus atlanticus can be up to 3 centimetres (1.2 in) in length.[3] It is silvery grey on its dorsal side and dark and pale blue ventrally. It has dark blue stripes on its head. It has a tapering body which is flattened, and has six appendages which branch out into rayed, finger-like cerata.
INTERESTING FACTS - it has the ability to hide from predators. - it has a sac of gas in its stomach. - the blue dragon looks like it has a real tail but watch out it has stinging Cells. - the blue slug will slowly make it's way to the pray using it's big jazz hands things.