Amphibious. The Mizutsune can breathe air and water.
Multiattack: 2 attacks Bite. Melee attack: +7 to hit, reach: 5 ft.. Hit: 2d6+4 piercing damage Tail. Melee attack: +7 to hit, reach: 10 ft.. Hit: 1d8+4 piercing damage and dex save dc: 15 or knocked prone Bubble Prison. The creature is Slick and enclosed in a bubble of shimmering force for 1 minute or until the bubble is destroyed. Nothing, not physical Objects, energy, or other spell effects, can pass through the bubble, in or out, though a creature in the Sphere can breathe there. In addition the inside of the bubble is treated as having no light and any creature inside cannot see outside of the bubble. A creature inside of the bubble automatically hits any attacks directed at the bubble. The bubble has AC 15, 30 hit points, resistance to bludgeoning damage, immunity to poison and psychic damage, but vulnerable to piercing damage. At the end of the mizutsune's turn all bubbles rise 10 feet higher into the air. Breath weapon. Recharge 5-6, A 60 ft. line of pressurized water, Dex save dc 17. Fail: 8d6 bludgeoning damage, Save: half damage