The blue sea slug, also known as Glaucus atlanticus, is a small marine gastropod found in warm ocean waters. It is easily recognizable by its vibrant blue color and unique shape, resembling a tiny dragon. This creature floats on the surface of the water, using its gas-filled sac to stay buoyant. The blue sea slug feeds primarily on jellyfish, which it captures using its specialized tentacles. It has a fascinating defense mechanism; when it consumes jellyfish, it can store their stinging cells and use them for its own protection against predators.