From Team Fortress Wiki
Cadaver's Cranium is a community-created headwear item for the Heavy. It is an enlarged forehead stapled to the Heavy's skull, with thin black hair atop, based on popular culture 'Frankenstein's monster' portrayals.
- The Cadaver's Cranium was added to the game.
- When a Heavy wearing the Cadaver's Cranium is ÜberCharged, the hat will appear darker in areas, causing a noticeable difference between the hat and the Heavy's actual skin.
- The developmental name for this hat was "Frank's Hat" and it had 2 bolts going into the sides of the Heavy's neck before Valve renamed it and added it to the Scream Fortress update.
- Like several other Halloween hats, the Cadaver's Cranium does not have a randomly selected level when found or purchased. Its level is always 31, presumably because Halloween is on the 31st of October.
- Cadaver is another word for a dead human body, often used to describe a body in medical training or research.