She appeared in the episode An Ice Girl for Boomer.
A heat wave thawed her out of the Ice Cave. When Boomer thought Rebecca had declined his offer to go on a date with him to the luau, Brady found Un-gela. When he asked her what her name was she said "Uhn." He decided it was short for "Un-gela." He used Mikayla's things to turn Un-gela into a "lady." He then set her up with Boomer. However, Rebecca arrived to go to the luau with Boomer, so Brady trapped Un-gela in the vault.
She broke out and ran to the Ice Cave, where she started acting like a Neanderthal again and put on her old clothes. She then attacked Rebecca at the luau.
The Cave Man thawed out and ran to get Boomer back because he thought Boomer stole Un-gela from him. He captured Rebecca and took to the roof of The Castle. Boomer talked to Un-gela and made her realize that the Cave Man really liked her, so she persuaded him to let Rebecca down. (An Ice Girl for Boomer)