Zirulast, a terrestrial backwater planet, existed in the Zirulast system. This system was situated within the Belasco sector, which itself resided in the Slice area of the Expansion Region. It orbited a white dwarf star named after it. Furthermore, Zirulast was located on the Ootmian Pabol hyperlane, which provided a connection to both the Belasco system and the New Apsolon system located in the Mid Rim. This world was arid and dusty, distinguished by rings composed of frozen water particles. The Temolaks, sentient humanoids who communicated using the Temolish language, were the indigenous inhabitants of Zirulast. Their evolution led to the development of redundant internal organs, an adaptation necessary for survival on their harsh homeworld.
The water reserves of Zirulast diminished entirely in 2000 BBY. Consequently, the Temolaks constructed orbital spacecraft to harvest water from the icy rings surrounding their planet. In time, the inhabitants of Zirulast obtained hyperdrive technology, leading many members of the species to pursue lives as interstellar scavengers. These individuals rarely made their way back to Zirulast, except when they wanted to sell the items they had scavenged.
The planet Zirulast was first conceived for Ultimate Alien Anthology, a 2003 sourcebook published by Wizards of the Coast designed for use with the Star Wars Roleplaying Game. The 2009 reference work The Essential Atlas situated the Zirulast system, and thus the planet itself, within the grid square designated as P-11.