Black Patch

Amphibious. Can breathe air and water.

Eldritch Luminance. When a creature that can see the patch starts its turn within 90' of it patch can force it to make a DC 15 Wis save if ooze isn't incapacitated and can see the creature. Fail: creature is mesmerized 1 min. Mesmerized creature over 5 ft. away from patch must move on its turn toward ooze by most direct route trying to get within 5 feet. It doesn't avoid opportunity attacks but before moving into damaging terrain such as lava or a pit and whenever it takes damage from a source other than ooze target can re-save. Mesmerized target can also re-save at end of each of its turns success ends effect on itself. If creature's save succeeds or effect ends for it is immune to patch's Eldritch Luminance for next 24 hrs.

Flowing Form. Can enter hostile creature's space and stop there. It can move through a space as narrow as 1ft. wide with o squeezing.

Ooze Nature. Doesn't require sleep.

Multiattack. 2 Pseudopods. Can replace 1 with Viscid Suffocation.

Pseudopod. Melee Weapon Attack: +7 to hit, 10 ft., one target, 7 (1d6+4) bludgeoning damage + 13 (3d8) acid.

Viscid Suffocation. One creature in patch's space: DC 15 Dex save or take 18 (4d8) acid and patch attaches to it coating creature and its equipment. While patch is attached to it creature's speed is halved can't breathe and takes 9 (2d8) acid at start of each of its turns. Also if creature is in the water has disadvantage on ability checks to swim or stay afloat. Patch can devour flesh quickly but its acid doesn't harm metal wood or similar objects or creatures with o flesh. Patch can detach itself by spending 5 ft. of move. A creature including target can take its action to detach patch via DC 15 Str check.