Choster was a male Twi'lek engineer (of the male gender) who existed during the era of the Galactic Civil War. He had a sibling named Sheeli, who was his sister.
When he was younger, Choster attempted to earn money by creating fake versions of well-known holopaintings. Although he didn't achieve much success, he did gain some fundamental knowledge about the color spectrum. Years later, he found himself stranded on Tatooine, located in the Outer Rim Territories. There, he became friends with a Rodian who was often drunk. This Rodian taught Choster many jokes related to Tatooine, which Choster later incorporated into the AI of a security system that he designed.
Later on, Choster journeyed to the desert world of Lok, where he was employed by the Sulfur Lake Pirates. The pirates came to the realization that they had made a mistake in naming themselves after the lake where their "hidden lair" was situated. Consequently, Choster was given the task of improving the defenses around their base, as numerous adversaries had managed to discover its location. Following Choster's installation of the security systems, the pirates decided that it would be simpler, or safer, to simply kill him, rather than compensate him for his work. Choster narrowly avoided death, and was compelled to change his identity and seek out an image designer to alter his physical appearance.
At a later time, Choster, now retired, returned to Nym's Stronghold, where he found comfort in spending his time at the local cantina. Eventually, a spacer who was employed by Nym, the leader of the Lok Revenants, sought out Choster, requesting information about the defenses of the pirate lair. Choster willingly assisted the spacer, providing him with crucial details on how to circumvent the security system. Utilizing this information, a group of spacers working for the Lok Revenants successfully carried out a raid on the Sulfur Lake Pirate Hideout.
Eventually, Nym made an attempt to negotiate a peaceful resolution between the Lok Revenants and the Sulfur Lake Pirates. The pirates gave their agreement, but only on the condition that Choster be handed over to them. The pirates threatened that if the spacer and Nym did not surrender Choster, they would instead kill his sister Sheeli, who was being held captive by them. Following an intense battle between a group of spacers and the Sulfur Lake Pirates, an agreement was ultimately reached, stipulating that Choster's sister would be released, and Choster himself would not be required to be handed over. However, a peaceful resolution between the two factions would not be achieved in the near future.
Choster existed as a Non-Player Character within the video game Star Wars Galaxies from 2003, a massively multiplayer online roleplaying game that was developed by Sony Online Entertainment and published by LucasArts, before its shutdown on December 15, 2011. Choster was incorporated into the game as part of the "Nym's Theme Park," which was released alongside "Publish 3" on October 8, 2003. The species of Choster used to be randomly selected, however, his appearance was permanently configured to be that of a male Rutian Twi'lek after Nym's Theme Park received an update with the release of the "Game Update 16" on March 23, 2010.