Bowser, King of the Koopas

Fiery Shell. When a creature within 5 feet of Bowser hits him with a melee attack, the attacker takes 7 (2d6) fire damage.

Thick Hide. Bowser has resistance to magic missile, and advantage on saving throws against being grappled or restrained.

Legendary Resistance (3/Day). If Bowser fails a saving throw, he can choose to succeed instead.

Multiattack. Bowser makes three attacks: one Bite, one Claw, and one Stomp.

• Bite. Melee Weapon Attack: +13 to hit, reach 5 ft., one target.
  Hit: 24 (4d6 + 8) piercing damage.

• Claw. Melee Weapon Attack: +13 to hit, reach 10 ft., one target.
  Hit: 20 (3d8 + 8) slashing damage.

• Stomp. Melee Weapon Attack: +13 to hit, reach 5 ft., one target.
  Hit: 21 (3d10 + 8) bludgeoning damage. Medium or smaller creatures must succeed on a DC 18 Strength saving throw or be knocked prone.

• Flame Breath (Recharge 5–6). Bowser exhales fire in a 60-foot cone. Each creature in that area must make a DC 19 Dexterity saving throw, taking 63 (18d6) fire damage on a failed save, or half as much on a success. Flammable objects ignite.

Shell Slam (Recharge 6). Bowser leaps into the air and slams down in his spiked shell. Each creature within 15 feet must make a DC 19 Dexterity saving throw or take 31 (7d8) bludgeoning damage and be knocked prone.

Bowser can take 3 legendary actions, choosing from the options below. Only one legendary action can be used at a time and only at the end of another creature’s turn. He regains spent legendary actions at the start of his turn.

• Move. Bowser moves up to his speed without provoking opportunity attacks.

• Smash. Bowser makes a Claw or Stomp attack.

• Fire Burst (Costs 2 Actions). Bowser creates a fiery explosion around himself in a 10-foot radius. Each creature in the area must succeed on a DC 18 Dexterity saving throw or take 22 (4d10) fire damage.