Boom Boom Artwork - Super Mario Bros. 3
Boom Boom is one of Bowser's henchmen. He makes multiple appearances in HTFA Land as mid-world bosses, usually located in castles. When it comes to damaging him, stomping on his head is more effective, dealing far more damage than from hitting him with balls/orbs or damaging Special Powers. Whenever you do so, however, he crouches and exposes the spikes on his shell for a short time.