Glabrezu

If the glabrezu dies outside the Abyss, its body dissolves into ichor, and it gains a new body instantly, reviving with all its Hit Points somewhere in the Abyss.

The glabrezu has Advantage on saving throws against spells and other magical effects.

The glabrezu makes two Pincer attacks and uses Pummel or Spellcasting.

Melee Weapon Attack: +9 to hit, reach 10 ft.. Hit: 16 (2d10 + 5) slashing damage. If the target is a Medium or smaller creature, it has the Grappled condition (escape DC 15) from one of two pincers.

Dexterity Saving Throw: DC 17, one creature Grappled by the glabrezu.
Failure: 15 (3d6 + 5) bludgeoning damage.
Success: Half damage.

1 use per day. The glabrezu casts one of the following spells, requiring no Material components and using Intelligence as the spellcasting ability (spell save DC 16):
At Will: Darkness, Detect Magic, Dispel Magic
1/Day Each: Confusion, Fly, Power Word Stun