Adult Pink Dragon

Amphibious. The dragon can breathe both air and water.

Legendary Resistance (3/Day). If the dragon fails a saving throw, it can choose to succeed instead.

Multiattack. The dragon can use its Comedic Presence. It then makes three attacks: one with its bite and two with its claws.

Bite. Melee Weapon Attack: +10 to hit, reach 10 ft., one target. Hit: 16 (2d10 + 5) piercing damage plus 7 (2d6) force damage.

Claw. Melee Weapon Attack: +10 to hit, reach 5 ft., one target. Hit: 12 (2d6 + 5) slashing damage.

Tail. Melee Weapon Attack: +10 to hit, reach 15 ft., one target. Hit: 9 (1d8 + 5) bludgeoning damage.

Comedic Presence.  Each creature of the dragon's choice that is within 120 ft. of the dragon and aware of it must succeed on a DC 19 Wisdom saving throw or be thrown into a fit of laughter for 1 minute. While laughing, the creature falls prone, becoming incapacitated and unable to stand up for the duration. A creature with an Intelligence score of 4 or less isn't affected. A creature can repeat the saving throw at the end of each of its turns or anytime it takes damage, 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 dragon's comedic presence for the next 24 hours. If the dragon uses its comedic presence and is unable to affect a single creature, it can immediately make a tail attack. 

Breath Weapons (Recharge 5–6) The dragon uses one of the following breath weapons:

Dream Breath. The dragon exhales mist in a 90-foot cone. Each creature in that area must succeed on a DC 18 Constitution saving throw or fall unconscious for 10 minutes. This effect ends for a creature if the creature takes damage or someone uses an action to wake it.

Bubble Breath.  The dragon exhales goopy bubbles in a 60-foot cone. Each creature in that area must make a DC 18 Dexterity saving throw to avoid becoming covered in slippery slime. All creatures that fail their saving throw are blinded for 1d4 rounds. The area where the dragon exhaled its bubbles becomes difficult terrain and every creature who wishes to move within the area must succeed on a DC 14 Dexterity saving throw for every 15 feet of movement they wish to make, falling prone on a failed save. After 10 minutes the bubbles fade and the area is no longer affected.

Spellcasting. The dragon casts one of the following spells, requiring no spell components and using Charisma as the spellcasting ability (spell save DC 19):

At will: hideous laughter

2/day each: charm person, hold person

1/day each: animate objects, compulsion, polymorph

Change Shape. The dragon magically transforms into any creature that is Medium or Small, while retaining its game statistics (other than its size). This transformation ends if the dragon is reduced to 0 hit points or uses a bonus action to end it.

The dragon can take 3 legendary actions, choosing from the options below. Only one legendary action option can be used at one time and only at the end of another creature’s turn. The dragon regains spent legendary actions at the start of its turn.

Mock. The dragon casts Hideous Laughter (DC 19).

Tail Attack.  The dragon makes a tail attack.

Good Impression (Uses 2 Actions).  The dragon casts a spell it has seen another creature cast within the past hour. The dragon’s save DC is 19 and its spell attack modifier is +11.