Mustafar was a lava planet that appeared in the ambush game, Haters of the Jedi II: Order 66.
Mandalorian base ( 21 ~ 19 BBY)Edit
Somewhere between 21 and 19 BBY Boba Fett traveled to Mustafar to set up a Mandalorian outpost. This base was later attacked by Pindus Zwervus and his second hater group. But they did not manage to destroy it because they got betrayed by Tauntaun .