Black Slaad

Innate Spellcasting. The slaad's innate spellcasting ability is
Charisma (spell save DC 19). The slaad can innately cast the following spells, without providing material components:

At will: detect magic, detect thoughts, invisibility,(self only), mage hand, major Image

3/day each: circle of death, dispel magic, fear, fly, tongues

1/day each: finger of death, plane shift, maddening darkness, power word kill

Magic Resistance. The slaad has advantage on saving throws against spells and other magical effects.

Magic Weapons. The slaad's weapon attacks are magical.

Regeneration. The slaad regains 10 hit points at the start of its turn if it has at least 1 hit point.

Shapechanger. The slaad can use its action to polymorph into a Small or Medium humanoid, or back into its true form. Its statistics, other than its size, are the same in each form. Any equipment it is wearing or carrying isn't transformed. It reverts to its true form if it dies.

Multiattack. The slaad makes three attacks: one with its tongue and two with its claws. If both claw attacks hit the same creature, the target takes 9 (2d8) slashing damage and must succeed on a DC 21 Constitution saving throw or be stunned until the end of its next turn.

Tongue. Melee Weapon Attack: +13 to hit, reach 15 ft., one target. Hit: 16 (2d8 + 7) piercing damage plus 7 (2d6) necrotic damage.

Claw. Melee Weapon Attack: +13 to hit, reach 5 ft., one target. Hit: 16 (2d8 + 7) slashing damage plus 7 (2d6) necrotic damage.

Chaos Spittle. Ranged Weapon Attack: +12 to hit, range 60 ft., one target. Hit: Roll 1d8 to determine what effect happens:

1. The target takes 35 (10d6) fire damage.
2. The target takes 35 (10d6) acid damage.
3. The target takes 35 (10d6) lightning damage.
4. The target takes 35 (10d6) poison damage.
5. The target takes 35 (10d6) cold damage.
6. The target is restrained. lt must then make a DC 20 Constitution saving throw at the end of each of its turns. If it successfully saves three times, the effect ends. If it fails its save three times, it permanently turns to stone and is subjected to the petrified condition. The successes and failures don't need to be consecutive; keep track of both until the target collects three of a kind.
7. The target is blinded. lt must then make a DC 20 Wisdom saving throw at the start of the slaad's next turn. A successful save ends the blindness. lf it fails that save, the creature is transported to another plane of existence of the DM's choosing and is no longer blinded. (Typically, a creature that is on a plane that isn't its home plane is banished home, while other creatures are usually cast into the Astral or Ethereal planes.)
8. Two effects. Roll twice more, rerolling any 8.

The slaad can take three 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. The slaad regains spent legendary actions at the start of its turn.

Tongue. The slaad makes a tongue attack.

Move. The slaad moves up to half its speed without provoking opportunity attacks.

Chaos Spittle (Costs 2 Actions). The slaad makes an acid spittle attack.

Cast a Spell (Costs 2 Actions). The slaad casts a spell from its list of innate spells, using a spell slot as normal.