The beldon is an enormous gas-filled creature native to the skies of Bespin. Beldons metabolize the natural chemicals and biospheric planktons of the slushy gas-liquid-solid interface of Bespin's lower atmosphere via long, trailing tentacles. They travel in free-floating herds. Beldons reproduce sexually, but do not mate: eggs and sperm are released into the atmosphere and drift like plankton until random fertilization occurrs.

Beldons excrete Tibanna gas, which could be collected and used as hyperdrive coolant. They are surrounded by a small electrical field to detect approaching predators, like velkers.

Some rare species of beldon can actually survive in space, drifting in interstellar nebulae or gas clouds. They can also consume minerals in small planetoids and asteroids by secreting acid on their tentacles to bore into rock and metal. They have been known to even latch onto crippled starships for their mineral content. Like the beldons on Bespin, these "space beldons" also excrete Tibanna gas.