Mon*Star is an alien mafia boss called Mon*Star's Mob, an organized crime group that commits crimes throughout Limbo. At first, Mon*Star was caught by Commander Stargazer, a bionic cop who is the boss of SilverHawks.
Mon*Star was placed in the prison cell of the planet Penal 10. But he managed to escape by changing his form into an armored monster because of the light from Moonstar Limbo.
Before turning into an armored monster, Mon*Star was a muscular cat humanoid with black hair streaked with red all over, a thick red mane and beard, and an eye patch with a black star symbol covering his left eye. Utilizing the light from Moonstar Limbo he transformed his body into a spiked armored monster as he recited "Moonstar of Limbo, give me the might, the muscle, the menace, of MON*STAR!".
In this state, he temporarily regained his left eye with it being able to shoot out rays of red Star Light which had various effects, both destructive and stunning.