Armour as plate and shield, Move 100' Flying/Ground/Swim/Tunnel, 30 Hit Dice, 270 HP, 4d12 Dam (Dark Coils) 4d8 Dam (Devouring 'Maw') Morale 12
4 Attacks (3 Dark Coil, 1 Maw/1 Constrict)
Constrict. The Wyrm can make one constriction attempt instead of a Devouring 'Maw' effort. 4d12 damage and target must save vs paralysis to avoid being grappled. Grappled target takes 4d12 damage each round and the Wyrm may continue to make attacks on others around it (it's a mile or so long). Grappled victim may attempt to free itself with a Strength check at -8 at the beginning of its turn.
War of the Monsters. The Wyrm can effectively force conflict between itself and any Titan, Demon or Old One. They must Save vs Magic at -8 to resist.
Frightful Presence. Save vs Paralysis or be stunned for d3 rounds.
Swallow. Makes one Devouring 'Maw' attack upon a target of huge or smaller. Target must make a save vs Death at -2 to avoid being swallowed. They take 9d6 damage at the start of each Wyrm turn.
Seize the Darkness. If underground, in space, in the night or otherwise surrounded by darkness, the EoNian Wyrm may repair itself of 8d6 HP. Leaves a space absent of anything for 24 hours.
EONIAN WYRM - AC 24, HP 820, Spd. 100ft Flight/Ground/Swim/Tunnel, +19, 6d12+10 dam (Dark Coils), 5d12+10 (Devouring 'Maw') XP 155,000 CR 30
S+10/D 0/C +10/I 0/W+8/C 0
Immune to fire, poison, bludgeoning, piercing and slashing from non-magical weapons. Cannot be blinded, charmed, frightened, paralysed or poisoned.
Legendary Resistance (3/Day). If the Wyrm fails a saving throw, it can choose to succeed instead.
Destroyer. The Wyrm deals double damage against structures.
Multi Attack.The EoNian Wyrm can use its Frightful Presence. Then The Wyrm attacks 5 times with its endlessly rotating, grinding coils before making a Devouring Maw attack or a Swallow attack.
Constrict. The Wyrm can make one constriction attempt as a bonus action. +19 to hit, deals 6d12+10 damage and target is grappled. DC-22 to escape.
War of the Monsters. The Wyrm can effectively force conflict between itself and any Titan, Demon or Old One that is of at least CR 25. Target must succeed in an opposed Wisdom check to resist. If the target fails, it must abandon whatever it is currently doing to face the Wyrm in battle.
Frightful Presence. Any creature within a mile of the EoNian Wyrm must succeed at a DC-24 Wisdom save else become frightened for 1 minute. Those affected can repeat the saving throw at the end of each turn. Passing the save grants immunity to Frightful Presence for 24 hours.
Swallow. Makes one Devouring 'Maw' attack upon a target of huge or smaller. Target must make a DC-18 Dexterity save to avoid being swallowed. Swallowed creatures are blinded and restrained. They take 18d6 damage at the start of each Wyrm turn.
Tail Lash. The Wyrm makes one Dark Coil attack.
Surge. The Wyrm moves up to half its speed in any direction. If it chooses to tunnel, it vanishes from sight, drawing all of its mile long body behind it in a maddening instant.
Seize the Darkness (Costs 2 actions). If underground, in space, in the night or otherwise surrounded by darkness, the EoNian Wyrm may repair itself of 16d6 HP. Leaves a space absent of anything for 24 hours.