Unga is a human cave child who is a fellow student in the same class that Grog is in the three-part cartoon show episode "The Smurfs That Time Forgot". She is the top student in her class who is always trying to out-do Grog in whatever she is learning from her teacher.
In "The Smurfs That Time Forgot", Unga went with her teacher on a field trip that Grog was prevented from going on due to his antics in the classroom. Of his own initiative, Grog went on his own field trip and came across a Smurf, namely Clumsy, who was searching for some rocks to start a fire with. He captured Clumsy when he discovered that he was able to start a fire with rocks, and with the Smurf hidden inside his tunic, he made himself king over his own class with the secret power of "the dancing lights", with Unga as one of his servants.
Unga served Grog for a while.