Whomp Stomp is a Mid-boss Battle mini-game. In "Solo" mode, he appears in Bob-omb Factory as a boss.
The minigame is a game with luck. You have to pick a number between 0 or 1. You have 10 seconds to decide. If it lands on you, you're unfortunate to earn -1 point and not be able to pound Whomp. When pounding Whomp, you earn +3 points. You have to pick a number between 0 or 1.
As Whomp rages, he'll add +1 or +2 turns by stomping on the number before you deciding a number.
The Wii Remote should be held vertically when playing.