Redjelly

Redjellies were a non-sentient species of aquatic creature which inhabited the Boiling Sea on the planet Drall. The creatures traveled in swarms and were light, translucent and delicate in nature. The sea they lived in was a brackish inland lake which was overgrown with kettleweed algae in the wet season and boiled in summer when the algae died on mass and released large amounts of gas.

Behind the scenes
Red jellies were first mentioned in Suns of Fortune, a sourcebook released in 2014 for Fantasy Flight Games Star Wars: Edge of the Empire roleplaying system.