The Sybrial brain slug was a species of slug named after the Sybrial system, which itself was located within the Vodilux sector. During the Galactic Civil War, which pitted the Galactic Empire against the Rebel Alliance, a Wookiee commandeered the starship belonging to a team of Alliance operatives. His goal was to execute a rescue mission for his family, who were being held at an Imperial prison situated on the planet called Branth. After one of the Rebels interpreted the Wookiee's explanation of his behavior for the ship's captain, the captain expressed his disagreement. The Wookiee then vocalized a boisterous statement in the Shyriiwook language. However, as the Rebel began to translate once more, the captain interrupted, stating that he understood the meaning of the Wookiee's words and likening the Rebel to a Sybrial brain slug.
"Wookiees Amok," a roleplaying adventure by Timothy M. Ryan, featured a mention of the Sybrial brain slug. This adventure was released in 1989 as part of the thirty-seventh issue of Challenge magazine, intended for use with Star Wars: The Roleplaying Game from West End Games.