Melllvar's Mom

She turns up mid-crisis as the unseen force that ends her son's rampage: a booming, exasperated voice calling Melllvar home like any parent hauling a child out of trouble. She has no patience for his tantrums, his grudges, or his taste in music, and she is not remotely impressed by his powers.

The joke is scale reversal — a cosmic, planet-threatening being instantly deflated by his mother's nagging — and Tress MacNeille plays her with the exact flat, weary authority of every parent yelling up the stairs. It lands the episode's climax as a punchline instead of a battle, which is funnier.