Captain Valas

Water Breather. Captain Valas can always breath under water.

Spellcasting. Captain Valas is a 20th-level spellcaster. Its spellcasting ability is Wisdom (spell save DC 18, +13 to hit with spell attacks). It has the following druid spells prepared:

Cantrips (at will): druidcraft, produce flame, shillelagh

1st level (5 slots): entangle, longstrider, speak with animals, thunderwave

2nd level (5 slots): animal messenger, barkskin

3rd level (4 slots): Counterspell, Call lightning, Wall of Water

4th level (4 Slots): Blight, Confusion, Ice Storm, Watery Sphere,

5th level (4 slots): Geas, Maelstrom, 

7th level (2 slots): Plane Shift, Reverse Gravity, 

8th level (1 slot): Control Weather, Feeblemind, Tsunami, 

9th level (1 slot): Foresight, Storm of Vengeance, True Resurrection

The Druid's Axe. Melee Weapon Attack: +14 to hit, reach 10 ft., one target. Hit: 6 (1d12) slashing damage +10 acid and +10 cold damage. (While Captain Valas wields the Druid's axe he adds +3 to targeted spell attacks. Also, He can cast hold person as a bonus action once per short rest. Wisdom saving throw of 16.)

Water Polymorph. Bonus Action: 2/short rest, Captain Valas can poly morph into water itself. In this form he can only be hurt by Lightning, Necrotic, Thunder, or Psychic damage. He has a move speed of 80' down hill, 40' on a flat surface, and 20' uphill. any damage while in this form will cause him to revert to his original form. He can also fit through any area that is not waterproof. He can also cast spells while in this form. 

Wild Shape. 2/long rest, Captain Valas can polymorph into any CR 8 or lower beast for 24 hours. (Huge Crab is his preferred polymorph)

Water Polymorph. When attacked with a targeted attack, Captain Valas can use his water polymorph to prevent damage.

Wild Shape. When Attacked, Valas can choose to wild shape as a reaction.

Absorb Elements.

Counterspell.