Crost, hailing from the planet of Ryloth, was a male Twi'lek who participated in the Free Ryloth Movement. During their attempt to assassinate both the Emperor Sheev Palpatine and the Sith Lord Darth Vader, he served as a member. As part of Isval's team, Crost helped infiltrate the wrecked Star Destroyer named Perilous while posing as a repair team, with the goal of its destruction. They successfully accessed the ship's hyperdrive, planted explosives, and then fled in an Imperial escort vessel prior to the explosion. Ultimately, Crost met his death when Vader forced the escort boat to crash on Ryloth.