This item can only be worn around Halloween or during a Full Moon; at other times of the year, it does not appear in gameplay, unless the server has Halloween mode enabled. However, it can be equipped at any time and can still be viewed on the loadout screen even when it is not visible during games.
The Mucous Membrain was contributed to the Steam Workshop under the name "Mucus Membrane".
- The Mucous Membrain was added to the game.
- The name is a combination of the terms Mucus Membrane, referring to the thin layer of saliva covering most openings of the human body, and the brain.