As John stated his wish, the creature's ears flapped and grew 3x times their size, as it's eyes glew bright white and it crackled with energy. It spoke in a high-pitched, and yet monotonous voice as it repeated his request.
"You have wished that your sister, Elaine would learn some respect, mind her manners, and try to act more polite or proper for once. So you have wished it, so it shall be."
As the room distorted and charged with white light, there was another boom coming from the creature similar to the Orb Shattering. Suddenly all was calm again. John looked upstairs, and slowly but surely the music went quiet. He could still hear it faintly, but it wasn't blasting up now. So he figured it must have worked possibly.
As he smiled, the creature burped and rolled cutely. He was so relieved with his wish, he didn't even notice it grow 2 inches as it followed behind him like a pet chained to it's owner.