Gossams were a small saurian species native to the planet Castell in the Colonies region of the galaxy, with colonies on the Outer Rim worlds of Felucia and Saleucami. Averaging slightly over one meter in height, Gossams had wrinkled skin, with narrowing, shriveled heads on elongated necks. Physical appearance was considered important in Gossam society, and females often curved their hair up from the back of their heads. They were bipeds, balancing their frail bodies on small feet, and had long three-fingered hands. The average lifespan of a Gossam was about seventy-five years.
Known for their shrewd and cunning nature, most Gossam on Castell served the Commerce Guild, which was headed by the Gossam Shu Mai during the Separatist Crisis and the Clone Wars. Due to their intelligent and scheming nature, Gossams could be found all over the galaxy, acting as either legitimate merchants or as law-breaking pirates and smugglers, while Force-using Gossam were extremely rare.