Blue dragons (or the blue glaucus) have washed up on the Padre Island National Seashore in Texas. These delicate creatures, not more than three centimetres long are actually a type of sea slug, but the park says the “rare find” has a “defense worthy of the name dragon.”

Also known as sea swallows or blue angels, blue dragons have been found floating through the Atlantic, Pacific, and Indian oceans in temperate waters, per Oceana, a nonprofit ocean advocacy organization. They’re typically very small (no bigger than three centimeters long) and have blue and silver coloring.

The blue dragon’s appearance actually works to its advantage. It floats on its backside, exposing its vibrant underbelly to airborne predators as a “stay away” signal, while its blue hues act as camouflage within the water. Its gray backside seamlessly merges with the surface of the ocean, keeping it well hidden from potential predators below.

The tiny-but-mighty swimmer is not to be messed with, thanks to its meal of choice: Portuguese man-of-wars, a jellyfish-like organism known for its painful sting. While the blue dragon is not venomous on its own, it stores the stinging cells from its prey, so it can release them in the future when it feels threatened, per Oceana. “Because they are able to concentrate the stinging cells together, their sting can be more painful than a man-of-war’s,” the park stated.