Armor Class 18 (natural armor)
Hit Points 136 (16d8 + 64)
Speed 30 ft.
Saving Throws Dex +10, Con +8, Cha +9
Skills Acrobatics +10, Deception +9, Perception +7, Performance +9, Sleight of Hand +10, Stealth +10
Damage Immunities necrotic, poison; bludgeoning, piercing, and slashing from nonmagical attacks
Condition Immunities charmed, exhaustion, frightened, paralyzed, poisoned
Senses darkvision 120 ft., passive Perception 17
Languages Abyssal, Celestial, Common, Gnomish, telepathy 120 ft.
Challenge 11 (7,200 XP)
Last Laugh. Unless it is destroyed in a manner amusing to the god of death that created it, the grim jester gains a new body in 1d20 days, regaining all its hp and becoming active again. The new body appears in a place of the god's choosing.
Mock the Dying. Death saving throws made within 60 feet of the grim jester have disadvantage.
Turn Resistance. The grim jester has advantage on saving throws against any effect that turns undead.
Undead Nature. The grim jester doesn't require air, food, drink, or sleep.
Necrotic Claw. Melee Spell Attack: +9 to hit, range 5 ft., one target. Hit: 14 (2d8 + 5) slashing damage plus 14 (4d6) necrotic damage.
Killing Joke. The grim jester tells an ancient, nihilistic joke to one creature it can see within 60 feet of it. The target must succeed on a DC 17 Wisdom saving throw or fall prone in a fit of laughter, becoming incapacitated and unable to stand up for 1 minute. A creature that fails this saving throw by 5 or more is reduced to 0 hp instead. The incapacitated target can repeat the saving throw at the end of each of its turns, taking 14 (4d6) necrotic damage on a failed save or ending the effect on itself on a success.
Spellcasting. The grim jester casts one of the following spells, requiring no components and using Charisma as the spellcasting ability (spell save DC 17):
At will: disguise self, grease
3/day each: magic mouth (as an action), mirror image
1/day each: mislead, seeming