Ephemeral hangman

An ephemeral hangman was an aberration of the Plane of Shadow

Description
Its form was little more than a mass of dozens of writhing black tendrils or tentacles, all entwined in a trunk-like body and with a gnashing fang-filled mouth at their heart. Appearing black as ink and nigh-unseen in darkness, it seemed to be made of pure shadow, yet it weighed almost. Usually standing erect to a height of, it appeared like an alien and animated tree. However, it could extend its tendrils out and lay itself as flat as a shadow on the floor.

Personality
On the rare occasions they did speak, ephemeral hangmen were known to use a certain dialect of Undercommon.

Society
An aberration formed from pure shadow, ephemeral hangmen were abnormal even among the denizens of the Plane of Shadow.

History
The origin of the ephemeral hangmen was unknown to all. A few sages theorized that they began as the Shadow Plane counterparts of a tentacled creature like the roper and that these "shadow selves" somehow achieved their own independent existence and sentience.