Creeper (Ghost)

Incorporeal Movement. The Creeper can move through other creatures and objects as if they were difficult terrain. It takes 5 (1d10) force damage if it ends its turn inside an object.

Sunlight Sensitivity. While in sunlight, the Creeper has disadvantage on attack rolls, as well as on Wisdom (Perception) checks that rely on sight.

Puddle. The Creeper can turn into a puddle, which must be detected by a DC 15 Perception check. If walked upon, the target is immediately affected by the Swallow action.

Gooey Reduction. Upon receiving 15 damage or more, the Creeper's AC is reduced by 2.

Immovable Weight. The Creeper cannot be moved by any force that is not itself.

Gooey Carapace. Anything that the Creeper touches with it's movement, or any of it's attacks becomes difficult terrain. If this difficult terrain is walked over by anyone other than the Creeper, they must succeed a DC10 dexterity saving throw or fall prone.

Swallow. The Creeper makes a cuddle attack against a single medium or smaller creature that it is grappling. If the attack hits, the creature is swallowed. While swallowed, the creature is blinded and restrained, it has total cover against attacks and other effects outside the Creeper, and it takes 7 (2d6) acid damage at the start of each of the Creeper turns.

If the Creeper takes 15 damage or more on a single turn from a creature inside it, the Creeper must succeed on a DC 20 Constitution saving throw at the end of that turn or regurgitate all swallowed creatures, which fall prone in a space within 10 feet of the Creeper. If the Creeper dies, a swallowed creature is no longer restrained by it and can escape from the corpse by using 30 feet of movement, exiting prone.