11
11 (5d6+5)
walk 10 ft., fly 30 ft.
Stealth +1
blindsight 60 ft.
1/4
The darkmantle can't use its blindsight while deafened.
While the darkmantle remains motionless, it is indistinguishable from a cave formation such as a stalactite or stalagmite.
Melee Weapon Attack: +3 to hit, reach 5 ft., one target. Hit: 6 (1d6 + 3) bludgeoning damage, and the darkmantle attaches to the target. If the target is Medium or smaller and the darkmantle has advantage on the attack roll, it attaches by engulfing the target's head, and the target is also blinded and unable to breathe while the darkmantle is attached in this way.
A 15-foot radius of magical darkness extends out from the darkmantle, moves with it, and spreads around corners. The darkness lasts as long as the darkmantle maintains concentration, up to 10 minutes (as if concentrating on a spell). Darkvision can't penetrate this darkness, and no natural light can illuminate it. If any of the darkness overlaps with an area of light created by a spell of 2nd level or lower, the spell creating the light is dispelled.
The monstrosity can take 0 legendary action, choosing from the options below. Only one legendary action can be used at a time and only at the end of another creature's turn. The monstrosity regains spent legendary action at the start of its turn.