The Ghastly Gibus is an unlockable headwear item wearable by all classes. It is a slightly damaged black gibus hat with the top nearly detached.

In a similar fashion to the Gentle Manne's Service Medal, this hat was originally earned by being one of the first 10,319 people to visit a hidden web page. The alternative method through which it now can be unlocked is to complete the Ghastly Gibus Grab Scarechievement by dominating a player who is wearing the hat. Unlike other Halloween items, the Ghastly Gibus is not seasonally restricted. Each Ghastly Gibus earned prior to the Scream Fortress Update was changed to a Ghastlier Gibus.