Booyahg Slave of the Great Old One

At the start of each of the goblin's turns, each creature of its choice within 5 feet of it must succeed on a DC 15 Wisdom saving throw or take 10 (3d6) psychic damage, provided that the goblin isn't incapacitated.

Booyahg Slave of the Great Old One can take the Disengage or Hide action as a bonus action on each of its turns.

The goblin's innate spellcasting ability is Charisma. It can innately cast the following spells (spell save DC 15), requiring no material components:

• At will: detect magic, jump, levitate, mage armor (self only), speak with dead
• 1/day each: arcane gate, true seeing

The goblin is a 14th-level spellcaster. Its spellcasting ability is Charisma (spell save DC 15, +7 to hit with spell attacks). It regains its expended spell slots when it finishes a short or long rest. It knows the following warlock spells:

• Cantrips (at will): chill touch, eldritch blast, guidance, mage hand, minor illusion, prestidigitation, shocking grasp
• 5th level (3 slots): armor of Agathys, arms of Hadar, crown of madness, clairvoyance, contact other plane, detect thoughts, dimension door, dissonant whispers, dominate beast, telekinesis, vampiric touch

Melee or Ranged Weapon Attack: +5 to hit, reach 5 ft. or range 20/60 ft., one target. Hit: 4 (1d4 + 2) piercing damage.