Amethyst Dolphin

Guiding Swim: The Amethyst Dolphin can choose to magically guide a ship or vessel within 60 feet of it. The ship gains advantage on checks to navigate hazards in the water while within 120 feet of the dolphin. The effect lasts as long as the dolphin stays within 120 feet of the vessel and can maintain concentration (as if concentrating on a spell).

Telepathic Connection: The Amethyst Dolphin can telepathically communicate with creatures it has seen or met before within 120 feet. This telepathic link lasts for 24 hours, regardless of distance, as long as both parties are on the same plane of existence.

Magical Resistance: The dolphin has advantage on saving throws against spells and other magical effects.

Regenerative Waters: If the Amethyst Dolphin is submerged in water, it regains 10 hit points at the start of each of its turns.

Tail Slap: Melee Weapon Attack: +8 to hit, reach 10 ft., one target. Hit: 20 (3d10 + 4) bludgeoning damage.

 Water Pulse (Recharge 5-6): The Amethyst Dolphin releases a burst of magical water in a 20-foot radius around itself. Each creature of the dolphin’s choice within that radius must make a DC 16 Dexterity saving throw, taking 45 (10d8) cold damage on a failed save, or half as much on a successful one.

 Healing Pulse (Recharge 6): The dolphin emits a powerful wave of healing energy. Each creature of its choice within 60 feet regains 45 (10d8 + 5) hit points. 

The Amethyst Dolphin can emit a radiant glow in a 30-foot radius. Creatures within the glow have advantage on saving throws against being frightened or charmed and gain temporary hit points equal to the dolphin's Charisma modifier (5). The glow lasts for 1 minute or until the dolphin ends it (no action required).