Uro, Titan of Nature's Wrath

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

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

Siege Monster. Uro deals double damage to objects and structures.

Amphibious. Uro can breathe air and water.

Freedom of Movement. Uro ignores difficult terrain, and magical effects can't reduce its speed or cause it to be restrained. It can spend 5 feet of movement to escape from nonmagical restraints or being grappled.

Multiattack. Uro makes three Vine Tentacle attacks, each of which it can replace with one use of Fling.

Bite. Melee Weapon Attack: +17 to hit, reach 5 ft., one target. Hit: 23 (3d8 + 10) piercing damage. If the target is a Large or smaller creature grappled by Uro, that creature is swallowed, and the grapple ends. While swallowed, the creature is blinded and restrained, it has total cover against attacks and other effects outside Uro, and it takes 42 (12d6) acid damage at the start of each of Uro's turns.

If Uro takes 50 damage or more on a single turn from a creature inside it, Uro must succeed on a DC 25 Constitution saving throw at the end of that turn or regurgitate all swallowed creatures, which fall prone in a space within 10 feet of Uro. If Uro dies, a swallowed creature is no longer restrained by it and can escape from the corpse using 15 feet of movement, exiting prone.

Vine Tentacle. Melee Weapon Attack: +17 to hit, reach 30 ft., one target. Hit: 20 (3d6 + 10) bludgeoning damage, and the target is grappled (escape DC 18). Until this grapple ends, the target is restrained. Uro has ten vine tentacles, each of which can grapple one target.

Fling. One Large or smaller object held or creature grappled by Uro is thrown up to 60 feet in a random direction and knocked prone. If a thrown target strikes a solid surface, the target takes 3 (1d6)bludgeoning damage for every 10 feet it was thrown. If the target is thrown at another creature, that creature must succeed on a DC 18 Dexterity saving throw or take the same damage and be knocked prone.

Lightning Storm. Uro magically creates three bolts of lightning, each of which can strike a target Uro can see within 120 feet of it. A target must make a DC 23 Dexterity saving throw, taking 22 (4d10)lightning damage on a failed save, or half as much damage on a successful one.

Uro 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 kraken regains spent legendary actions at the start of its turn.

Vine Tentacle Attack or Fling. Uro makes one vine tentacle attack or uses its Fling.

Lightning Storm (Costs 2 Actions). Uro uses Lightning Storm.

Volcanic Cloud (Costs 3 Actions). While on land, Uro expels an smoke cloud in a 60-foot radius. The cloud spreads around corners, and that area is heavily obscured to creatures other than Uro. The heat and smoke make it very difficult to see and breathe in its reach. Each creature other than Uro that ends its turn there must succeed on a DC 23 Constitution saving throw, taking 16 (3d10) fire damage on a failed save, or half as much damage on a successful one. A strong wind current disperses the cloud, which otherwise disappears at the end of Uro's next turn.