ancient black scaled dragon kraken

3 legendary resistances,can choose to pass a failed save

breath weapons recharge on 5,6

 Acid Breath: The dragon exhales acid in a 60-foot line that is 10 feet wide. Each creature in that line must make a DC 24 Dexterity saving throw, taking 67 (15d8) acid damage on a failed save, or half as much damage on a successful one.

Sonic boom: the dragon kraken emits a loud explosive roar in a 30ft cone each creature in that cone must make a dc 24 str save or take 12d8 force damage are forced back 30ft and knocked prone, on a successful save they take half damage and moved 15ft  and are not prone 

multi-attack: makes 6 attacks 3 of them are with a tentacle

tentacle grab melee attack +19 to hit reach 20 ft range 1 target on a hit the target must make a dc24 dex save or is grappled and takes 5d10+10 damage and is constricted and half on a save a constricted creature can make a dc 24 str save at the end of their next turn.

tentacle slam sweeps in a 30ft cone in front of the dragon kraken, all creatures in the cone must make a dc 19 dex save or take 8d10+4 bludgeoning and knocked prone, half damage on a successful save and not knocked prone.

bite 10 ft range 1 target +19 to hit on a hit deals 4d12+10 piercing damage, a bit creature must make a dc 24 str save or is swallowed whole and takes 2d10 acid damage each round in the dragon krakens stomach

bonus action can cast healing word on itself as if it was a 8th level spell 3 times a day heals for 8d4 

has 3 legendary actions that can be taken at the end of another creatures turn. can only make one legendary action  per round.

deep dive, dives under the water attempting to hide, it moves its max movement speed left

extra tentacle attack