From Team Fortress Wiki
be the last time you see me.
— The Spy, on becoming invisible
The Under Cover is a headwear item for the Spy. It is a wide-brimmed hat that sits atop a set of bandages that completely covers the Spy's head.
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.
October 27, 2011 Patch (Very Scary Halloween Special)
- The Under Cover was added to the game.
- The hat and bandages are based on those worn by Griffin, the main character from the novel The Invisible Man, upon which the Invisible Rogue costume set is based.