Bowser

Multiattack. Bowser can make three attacks: one with his bite and two with his claw or one with his breath weapon.

Bite. Melee Weapon Attack: +12 to hit, reach 10 ft., one target. Hit: 24 (2d10 + 7) piercing damage.

Claw. Melee Weapon Attack: +12 to hit, reach 5 ft., one target. Hit: 16 (2d6 + 7) slashing damage.

Fire Breath (Recharge 5-6). Bowser exhales fire in a 60-foot line that is 10 feet wide. Each creature in that line must make a DC 19 Dexterity saving throw, taking 63 (18d6) fire damage on a failed save, or half as much damage on a successful one. The fire ignites flammable objects in the area that aren't being worn or carried.

Shell Slam. Bowser jumps into the air and slams down with his shell. Each creature in a 20-foot radius must make a DC 19 Strength saving throw or take 36 (4d12 + 7) bludgeoning damage and be knocked prone. On a successful save, the creature takes half damage and isn't knocked prone.

Summon Koopas (2/Day). Bowser can summon 1d4 Koopa Troopas, 1d3 Koopa Paratroopas, or 1d2 Hammer Bros. as reinforcements. These minions act on Bowser's initiative and follow his commands.

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

• Claw Attack. Bowser makes a claw attack.
• Shell Dash (Costs 2 Actions). Bowser moves up to his speed in a straight line and makes a bite attack against a creature in his path.
• Roar (Costs 3 Actions). Bowser lets out a fearsome roar. All creatures of Bowser's choice within 60 feet of him must succeed on a DC 17 Wisdom saving throw or become frightened for 1 minute. A creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.