Frix is a high-ranking officer in the Toad Empire who serves as an assistant to the Toad Air Marshall. He is the nearly-identical brother of Frax (they can only be told apart because Frix's chin is slightly bigger and he has a nervous twitch in his left eye).
Frix, along with Frax, appears on Planet Rat. The brothers are manning a large double-barrelled laser cannon under the Air Marshall's supervision. When the weapon gets destroyed by Bucky O'Hare and his crew, the two brothers run off with the Air Marshall and are never seen again.