Beldon

Beldons were a gigantic species native to the gas giant Bespin. They lived in large herds in the planet's lower atmosphere where they gathering atmospheric plankton and chemicals with long tendrils that fell from their bodies. Beldons metabolised the plankton and chemicals into tibanna gas, which was a valuable commodity which formed the basis of Bespin's economy. Beldons could measure anywhere between 0.8 and 10 kilometers in width and had bodies filled with orange gas bladders that allowed them to float and fleshy fins they could use for propulsion.

Behind the scenes
Beldons were created for Galaxy Guide 2: Yavin and Bespin, a Star Wars Legends reference book written by Jonatha Ariadne Caspian and released in 1989 by West End Games. The species were confirmed to be canon by the reference book Ultimate Star Wars, which was released in 2015.