An early 1800s coquilla  bug bear snuff box . Well carved on both sides with a gentleman's head on both sides, with a hat, hair, carved face etc.
It measures 7.5cm l x 4.5cm w.
A bugbear was a folkloric creature, and the term became a playful label for grotesque or humorous carved figures. In treenware, bugbear snuff  boxes were usually:
Carved from coquilla nut or boxwood or other fine-grain hardwoods.
Depicting a grotesque or humorous face on one end
Hollowed inside and used to carry snuft (powdered tobacco).
Often detailed with elaborate  carvings like soldiers, animals, or floral designs