Water Slime

Ooze. The slime takes up its entire space. Other creatures can enter the space, but a creature that does so is subjected to the slime's Suffocating Embrace and has disadvantage on the saving throw. The slime can hold only one Large creature or up to four Medium or smaller creatures inside it at a time.

Pseudopod. Melee Weapon Attack: +4 to hit, reach 5 ft., one creature. Hit: 10 (3d6) bludgeoning damage.

Suffocating Embrace. The slime moves up to its speed. While doing so, it can enter Large or smaller creatures' spaces. Whenever the slime enters a creature's space, the creature must make a DC 12 Dexterity saving throw. On a successful save, the creature can choose to be pushed 5 feet back or to the side of the slime. A creature that chooses not to be pushed suffers the consequences of a failed saving throw. On a failed save, the slime enters the creature's space, and the creature is engulfed. The engulfed creature can't breathe, unless it has the ability to breathe water. When the slime moves, the engulfed creature moves with it. An engulfed creature can try to escape by taking an action to make a DC 12 Strength check. On a success, the creature escapes and enters a space of its choice within 5 feet of the slime.

Water Absorption. The slime is able to absorb water into its body from water sources such as puddles or streams to heal its wounds. If the slime is within 5 feet of a body of water, it heals hit points according to the size of the body of water. If the body of water is significantly smaller than the slime, such as a puddle, it heals 1d4 hit points. If the body of water covers at least half of the slime, it heals 1d8 hit points. If the slime is fully immersed in a larger body of water, it heals 2d6 hit points.