Tromonids were creatures, native to the planet Rywin, imbued with a fatal bite. Months after their discovery, they infested five planets due to their high reproduction rate. At one time, Jabba Desilijic Tiure dealt with Gaar Suppoon where one of these creatures was a trade item. Later, Jabba found, with a gleam of rage, that Suppoon had actually given him a sterile member of the species. Jabba later released the creature, which bit Suppoon. The Hutt, of course, used the situation to his advantage, forcing Suppoon to give him all his trade items in exchange for a cure.