Canticaeli

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

Siege Monster. The canticaeli deals double damage to objects and structures.

Multiattack. The canticaeli makes one Bite attack, two Slam attacks and one Tail attack.

Bite. Melee Weapon Attack: +14 to hit, reach 5 ft., one target. Hit: 19 (2d10 + 8) piercing damage plus 9 (2d8) cold damage.

Slam. Melee Weapon Attack: +14 to hit, reach 15 ft., one target. Hit: 21 (2d12+ 8) bludgeoning and the target must succed on a DC 18 Strengh saving throw or be knocked prone.

Tail. Melee Weapon Attack: +14 to hit, reach 15 ft., one target. Hit: 19 (2d10 + 8) piercing damage plus 10 (3d6) poison damage.

Elemental Storm (Recharge 6). The canticaeli magically exhales a fierce elemental storm. The storm is a 60 ft. cone. Each creature in the storm must make a DC 24 Strength saving throw. On a failed save, a creature takes 45 (7d12) lightning damage and 9 (2d8) thunder damage. On a successful save, a creature takes half as much damage.

The canticaeli 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 leviathan regains spent legendary actions at the start of its turn.

Sudden Move. The canticaeli moves up to its fly speed provoking no opportunity attack.

Wing Blow (Costs 2 Actions). The canticaeli bats its gigantic wings. Each creature within 15 ft. of the canticaeli must succed on a DC 23 Dexterity saving throw or take 15 (2d6+8) bludgeoning damage and be knocked prone. The canticaeli can then move half its fly speed.