Nilz Yomm's biography includes that he was a Human physician of the male gender from the planet Roon. He was the spouse of Bola Yomm and the parent of Auren Yomm. Following Auren's victory in the Roon Colonial Games, Koong, who held the office of Governor on Roon, contaminated Umboo, their residential province, by introducing a chemical substance known as rooze. Bola became a victim of the poisoning, but Koong inadvertently poisoned himself as well. Koong summoned Nilz, but Nilz prioritized treating Bola. Sadly, he arrived too late to save Koong, who subsequently passed away.
The voice actor who played Nilz Yomm was Peter MacNeill.