Stygeon Prime, otherwise known as Stygeon, was a mountainous and snow-covered planet located in the Stygeon system of the Outer Rim Territories' Nuiri sector. The planet was 9,100 kilometers in diameter, and held a Type I atmosphere, with a mixture of oxygen, hydrogen and nitrogen, as well as a thin and cold climate. In orbit of a single star and orbited by two moons, Stygeon was almost completely devoid of native life, except for the large tibidee creatures that called it home.
The planet Stygeon Prime, referred to then as Stygeon, was first mentioned in the Blaster segment of Star Wars Insider 149, which discussed the upcoming Star Wars: Darth Maul—Son of Dathomir miniseries. It first appeared in the first issue. The planet's full name was revealed in Star Wars Rebels: The Visual Guide.