Blue dragon (Glaucus atlanticus) grows up to 1.2 inches (3 centimeters) long. Also known as a sea swallow or blue angel, it has three sets of ornate "wings' — called cerata — that makes it look a bit like a Pokémon. It floats upside down for better camouflage: The sea slug's bright blue coloring blends in with the surface of the water from above while its