Water Elemental

If the water elemental takes Cold damage, its Speed decreases by 20 feet until the end of its next turn.

The water elemental can enter an enemy's space and stop there. It can move through a space as narrow as 1 inch without expending extra movement to do so.

The water elemental makes two Slam attacks.

Melee Weapon Attack: +7 to hit, reach 5 ft.. Hit: 13 (2d8 + 4) bludgeoning damage. If the target is a Medium or smaller creature, it has the Prone condition.

Recharge 4–6. Strength Saving Throw: DC 15, each creature in the water elemental's space.
Failure: 22 (4d8 + 4) bludgeoning damage. If the target is a Large or smaller creature, it has the Grappled condition (escape DC 14). Until the grapple ends, the target has the Restrained condition, is suffocating unless it can breathe water, and takes 9 (2d8) bludgeoning damage at the start of each of the water elemental's turns. The water elemental can grapple one Large creature or up to two Medium or smaller creatures at a time with Whelm.
As an action, a creature within 5 feet of the water elemental can pull a creature out of it by succeeding on a DC 14 (Athletics).
Success: Half damage only.