Armor Class 13
Hit Points 58 (9d10 + 9)
Speed swim 60 ft.
Damage Resistances fire, [object Object]
Damage Immunities poison
Condition Immunities exhaustion, grappled, paralyzed, poisoned, restrained, prone, unconscious
Senses blindsight 30 ft., passive Perception 10
Languages understands Aquan but doesn't speak
Challenge 3
Invisible in Water. The water weird is invisible while fully immersed in water.
Water Bound. The water weird dies if it leaves the water to which it is bound or if that water is destroyed.
Constrict. Melee Weapon Attack: +5 to hit, reach 10 ft., one creature. Hit: 13 (3d6 + 3) bludgeoning damage. If the target is Medium or smaller, it is grappled (escape DC 13) and pulled 5 feet toward the water weird. Until this grapple ends, the target is restrained, the water weird tries to drown it, and the water weird can't constrict another target.
Monster Manual (2014), p. 299