Grumbmiller is a babysitter that Kai and Nya had when they were children. She was said to be mean and to have a large mole on an unspecified part of her body. When she made Kai and Nya go to bed early, they tripped her.
History
The Attack
When Kai and Nya were wondering how to defeat Buffmillion they decided to use the same tactic just like with Grumbmiller by tripping Buffmillion.