Casido was a human male who served as a Lieutenant under Admiral Gorin in the Imperial Navy of the Galactic Empire during the Galactic Civil War. He was stationed aboard the Imperial I-class Star Destroyer Intimidator while it was stationed above the planet Scarif, and was present aboard the bridge when the Alliance Fleet arrived above the planet during the Battle of Scarif. He was killed later in the battle when the Intimidator collided with the Star Destroyer Persecutor.