Water Kraken

Unusual Nature. The kraken does not require air, food, drink or sleep.

Immutable Form. The kraken is immune to any spell or effect that would alter its form.

Freedom of Movement. The kraken 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.

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

Multiattack. The kraken makes three tentacle attacks, each of which it can replace with one use of Fling, or it makes two stomp attacks. Then, it can produce spawn if it is available.

Stomp. Melee Weapon Attack: +14 to hit, reach 10 ft., one target. Hit: 28 (3d12 + 10) bludgeoning damage and if the target was a creature, they are knocked prone.

Tentacle. Melee Weapon Attack: +14 to hit, reach 60 ft., one target. Hit: 19 (3d6 + 10) bludgeoning damage, and the target is grappled (escape DC 18). Until this grapple ends, the target is restrained. The kraken has nine tentacles, each of which can grapple one target.

Fling. One Large or smaller object held or creature grappled by the kraken is thrown up to 90 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.

Produce Spawn (Recharge 6). The kraken sheds off pieces of its flesh, which quickly fold and unwrap themselves into horrible miniature copies of the creature. The kraken creates 1d4 spawnlings under its control in any space within 10 feet of it. If the space a spawnling appears in is occupied, the creature occupying that space is shunted into the nearest unoccupied space and knocked prone.

The kraken 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.

Move. The kraken moves up to half its speed without provoking opportunity attacks.

Awkward Leap (Costs 2 Actions). The kraken moves up to its speed, then jumps up to 40 feet.

Control Weather (Costs 3 Actions). The kraken uses its power over waves and weather, creating effects identical to the control weather spell, albeit the effects take place instantly. Then, it may make an attack with its tentacle action.