Mouma are giant, worm-like creatures that infest the asteroid, Beehay.
Mouma made their first appearance in "Lord Luud" when the Para brothers led Trunks, Pan, Goku and Giru into the tunnels of Beehay. The travelers from Earth soon lost track of the Para brothers, who had escaped the asteroid and left their pursuers to be eaten by the Mouma. In short order, the Mouma attacked the Earthlings' ship, forcing its crew to disembark and engage the creatures. While the Mouma proved resistant against energy attacks, such as the Kamehameha, Goku was able to subdue one by grabbing its tail, thrashing it about and throwing it into the asteroid walls. Trunks and Pan picked up on this technique, and the three of them were able to rid the area of the Mouma threat, at least temporarily.
Later, when the Para brothers returned and performed their signature dance that enslaves nearby listeners, the Mouma were also affected. Startled by the Mouma who had been drawn close, the brothers discontinued their dance and were immediately dispatched by the freed Goku, Trunks and Pan. Oddly, the Mouma were not seen in the aftermath.