Bongo Cat

Play the bongo: every creature within 100 ft and can hear this creature take 1000d20 damage.

Frightful Presence. Each creature of the bong cat's choice that is within 120 feet of the bongo cat and aware of it must succeed on a DC 3,500,000 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. If a creature's saving throw is successful or the effect ends for it, the creature is immune to the bongo cat's Frightful Presence for the next 24 hours.

smush. Melee Weapon Attack: +∞ to hit, reach 5 ft., all targets within range. Hit:  9999999d20 bludgeoning damage. 

loud music. RangedWeapon Attack: +∞ to hit, range 30/80 ft.,  all targets that can hear this creature. Hit: 1000d20 music damage.

Mist: This transforms into mist and can fit through small cracks and areas. It can move up to 100 ft. it mist form before returning to it's normal form.

Legendary resistance(always): if this fails a saving throw, this can choose to succeed instead.