Clingfilm

Ooze Wrap. The clingfilm takes up its entire space. Other creatures can enter the space, but a creature that does so is subjected to the cube's Wrap and has disadvantage on the saving throw.

Creatures wrapped inside the film can be seen but have near-total cover.

A creature within 5 feet of the clingfilm can take an action to pull a creature or object out of the clingfilm. Doing so requires a successful DC 12 Strength check, and if the creature making the attempt fails, it takes 7 (2d6) acid damage.

The clingfilm can hold only one Large creature or up to two Medium or smaller creatures inside it at a time.

Transparent. Even when the clingfilm is in plain sight, it takes a successful DC 15 Wisdom (Perception) check to spot a clingfilm that has neither moved nor attacked. A creature that tries to enter the clingfilm's space while unaware of its presence is surprised by the cube's Wrap and has disadvantage on the saving throw.

Pseudopod. Melee Weapon Attack: +3 to hit, reach 5 ft., one creature. Hit: 7 (2d6) acid damage.

Wrap. The clingfilm moves up to its speed, entering a Large or smaller creature's space. When the film enters a creature's space, the creature must make a DC 12 Dexterity saving throw.

On a successful save, the creature can choose to step 5 feet back or to the side of the clingfilm. A creature that chooses not move suffers the consequences of a failed saving throw.

On a failed save, the clingfilm enters the creature's space, and the creature takes 7 (2d6) acid damage and is wrapped up by the clingfilm. The wrapped creature is restrained, and takes 10 (3d6) acid damage at the start of each of the clingfilm's turns. When the film 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 clingfilm.

Transparent Trap. The clingfilm can take the Hide action as a bonus action, stretching itself out thinly into a Large space and regaining invisibility in regard to the Transparent ability.

Wrap. The clingfilm may use its Wrap ability whenever a Large or smaller creature enters its space.