Dry Bowser in NSMBU | Super Mario Maker Mod | BTG - YouTube

Bob-omb explosions, Shells, getting from below by a Spiny player, Icicles, Big Shoe ground pounds, charged Fire Clown Car fireballs and most other attacks deal 3 HP.
Big Shells and Big Bob-omb explosio… Bowser has 20 HP (40 HP when given a Super Mushroom), and most attacks do not instantly kill him but remove amounts of HP. Fire Mario, Yoshi and Fire Clown Car fireballs, Raccoon Mario's tail attack, Cape Mario's cape attack, and Shoe/Stiletto/Dry Bones Shell stomps deal 1 HP.
When HP reaches 0, he dies.