Corpse tearer linnorm

Legendary Resistance (3/Day). If the linnorm fails a saving throw, he can choose to succeed instead.

Magic Resistance. The linnorm has advantage on saving throws against spells and other magical effects.

Innate Spellcasting. The corpse tearer linnorm’s innate spellcasting ability is Wisdom (spell save DC 21 +13 to hit). The corpse tearer linnorm can innately cast the following spells, requiring no material components:

At will: fly

1/day each: animate dead, control undead, darkness, dimension door, enervation, etherealness, mage hand, protection from good and evil (good only), speak with dead, vampiric touch, water breathing 

Spellcasting. The Corpse tearer linnorm is a 17th-level spellcaster. Its spellcasting ability is Wisdom (spell save DC 17, +11 to hit with spell attacks). The corpse tearer linnorm has following death domain cleric spells prepared:
Cantrips (at will): mending, resistance, sacred flame, thaumaturgy, toll the dead
1st level (4 slots): bane, command, detect magic, false life, inflict wounds, ray of sickness 
2nd level (3 slots): blindness/deafness, continual flame, hold person, locate object, ray of enfeeblement 
3rd level (3 slots): animate dead, bestow curse, dispel magic, feign death, vampiric touch 
4th level (3 slots): banishment, blight, death ward, divination, freedom of movement
5th level (2 slots): antilife shell, cloudkill, contagion, insect plague
6th level (1 slots): harm
7th level (1 slots): symbol
8th level (1 slots): earthquake
9th level (1 slots): astral projection 

Multi attack. The corpse tearer linnorm makes one bite, two claws and one tail attack 

Bite. Melee Weapon Attack: +18 to hit, reach 20 ft., 1 target. Hit: 22 (4d6 + 10) piercing damage and the target must make a dc 10 constitution saving throw or gain 1 level of exhaustion. 

Claw. Melee Weapon Attack: +18 to hit, reach 10 ft., 1 target. Hit: 18 (2d8 + 10) slashing damage. 

Tail. Melee Weapon Attack: +18 to hit, reach 20 ft., 1 target. Hit: 20 (2d10 + 10) bludgeoning damage. 

Breath Weapons (Recharge 5–6). The corpse tearer linnorm uses one of the following breath weapons.

Paralysis breath. The corpse tearer linnorm exhales paralysis gas in a 60 ft cone and each creature within the radius must make a dc 23 Constitution saving throw or be paralyzed. A target that failed their save can remake the save again at the end of their turn. 

Disease breath. The corpse tearer linnorm exhales a disease filled slime in a 5 ft wide 120 ft long line and each creature within the radius must make a dc 23 Constitution saving throw or be diseased and until cured the constitution and strength stat of a creature is reduced by 1 every hour. If this drain reduces them to 0 constitution they die and this disease can only be magically cured.  

The corpse tearer linnorm can take 3 legendary actions, choosing from the options below. Only one legendary action option can be used at a time, and only at the end of another creature’s turn. The corpse tearer linnorm regains spent legendary actions at the start of its turn.

Tail (Costs 1 Actions). The corpse tearer linnorm makes a tail attack. 

Hurl target (Costs 2 Actions). The corpse tearer linnorm makes an apposed athletics check against a creature within 20ft. If they win the apposed check they can throw a creature in a direction of their choice up to 1d12 x 5ft and the target takes 1d10 per 5ft thrown. 

Crush (Costs 2 Actions). The corpse tearer linnorm jumps  up to 50ft away and when it lands any creature in the space the linnorm is jumping to must make a dc 23 Dexterity saving throw or be knocked prone and take 60 (10d12) bludgeoning damage and on their next turn they can attempt to make a dc 23 dexterity save to get out from under the linnorm to an adjacent square. On a successful save the target moves adjacent to the linnorm.