Demogorgon (5.5)

Huge Fiend (Demon), Chaotic Evil
Armor Class 22 (natural armor)
Hit Points 464 (32d12 + 256)
Speed 50 ft., swim 50 ft.
STR
29 (+9)
DEX
14 (+2)
CON
26 (+8)
INT
20 (+5)
WIS
17 (+3)
CHA
25 (+7)
Saving Throws Dex +10, Con +16, Wis +11, Cha +15
Skills Insight +11, Perception +19
Damage Resistances cold, fire, lightning
Damage Immunities poison; bludgeoning, piercing, and slashing that is nonmagical
Condition Immunities charmed, exhaustion, frightened, poisoned
Senses truesight 120 ft., passive Perception 29
Languages all, telepathy 120 ft.
Challenge 26 (90000 XP)     Proficiency Bonus +8
Legendary Resistance (3/Day).
Magic Resistance.
Two Heads.
ACTIONS
Multiattack.
Tentacle.
Gaze.
Spellcasting.
LEGENDARY ACTIONS
Gaze.
Tail.
Cast a Spell (Costs 2 Actions).

This full creature's stat block is not available (not OGL).

Demogorgon is the embodiment of chaos, madness, and destruction.
Monsters of the Multiverse
Demogorgon (5.5)