Water Weird
Source: Monster Manual (2024) p. 323

Water Weird
Servant of Primeval Magic
- Habitat. Underdark, Urban
- Treasure. Any
Serpentine nature spirits, water weirds protect pools, fountains, and magical bodies of water. In the water, these creatures are indistinguishable from the liquid surrounding them. Should their aquatic territory be disturbed, they rise as animate water spouts with vague snake- or dragon-like features. Often their appearance is enough to drive off foes, but if forced to fight, water weirds crush enemies within their fluid coils.
Water weirds might protect a site for generations and learn much about their surroundings. Some gain reputations as oracles and might respond to questions posed to them in Primordial. Since water weirds don’t speak, they often communicate using spouts of water or objects submerged in their pools.
Quote
Rule 2: Before you drink from a fountain or pool, toss a copper coin into it. It’s a small price to pay for your life!