Let's Read: The Dungeons and Dragons 5e Monster Manual!

[Mrmox42]

Darkmantle is relatively new monster, first appearing in 3e Monster Manual

The Darkmantle has, curiously enough, evolved from a 2. edition MM critter named the Executioners Hood, which was black, hung in the ceiling, and dropped on people, engulfing their head. It even had two holes that you could look out of, as you were being suffocated.
It was rather ridiculous, so somebody decided to evolve it into a something more sinister and 'natural' creature.

I liked the Executioners Hood, and I like the Darkmantle as well. They are not really that dangerous to a party, but they are still kind of creepy. Great at setting the mood in a dungeon.