Castor worked as a gardener aboard the Galactic Republic's Starlight Beacon space station. In the year 231 BBY, Administrator Velko Jahen of Starlight requested that Castor accelerate the flowering of the station's gardens for the visiting Galactic Agricultural Alliance, viewing it as a minor task because the gardens operated on a programmed timetable. After Head of Security Ghal Tarpfen observed that the gardens were already in bloom, Jahen remarked that she owed Castor her gratitude.
The character of Castor appeared in the debut of the short story "Starlight: Hidden Danger," authored by Justina Ireland. It was featured in issue number 203th of the Star Wars Insider magazine on June 22, 2021, as a component of the Star Wars: The High Republic: Starlight serialized narrative.