The Mauve Stinger is a small type of jellyfish that can be found in both Endless Ocean games.
"Its dome-shaped umbrella has eight feelers extending from the edge and four belt-shaped organs known as oral arms hanging down from the center. It has luminescent cells all over its body that light up when stimulated.
Many jellyfish in the class scyphozoa go through a stage living on the ocean floor as a polyp as they mature. This species develops in an unusual way, skipping this growth stage and moving on to the floating stage."
They float around, usually a solitary jellyfish among other creatures, like small fish or sea slugs. They respond well to being fed.