Bal is an Alien Baltan child from planet Kid78. He attends school with Maa and others, often playing the friendly rival, especially to Taa. Gutsun's father drives Bal to school, forcing the young Alien Guts to sprint the entire way. Bal frequently boasts about living in a mansion.

When Maa's group builds a rocket to help Maa find his parents, Bal has his mother purchase a custom rocket named the Bal. He tries to show it off to outshine the others, but an accident propels him into space. Stranded, he sends an S.O.S. signal, causing the Kids Star ship to merge with the Bal rocket. This forces the two crews to travel together.

Bal possesses massive claws, or scissors, on both hands. These function inconsistently, cutting objects like nets or seaweed but sometimes working like regular hands. He retains the Alien Baltan ability to create duplicate copies of himself through separation.

Bal harbors a significant romantic interest in Ultragirl Piko, making him vulnerable to manipulation through this affection. He once briefly developed feelings for a Seamon named Seamon after a fortune teller confused "mighty claws" with "mighty horn."

Bal's visual design evolved slightly between the initial television special and the subsequent series. His eyes became wider, his proboscis gained movement, and he was made taller.