The Bread Biter is a community-created cosmetic item for all classes. It is a bandanna based on a Bread monster's mouth (from the TF2 short film Expiration Date) that covers the class's lower face.
The Bread Biter was contributed to the Steam Workshop.
October 10, 2019 Patch (Scream Fortress 2019)
Steam Workshop thumbnail for the Bread Biter.