From BBC News:

A “spooky” image of a priest executed for treason over the Gunpowder Plot has appeared on a 17th century book thought to be bound in his skin, it is claimed.

Auctioneers said the face of Father Henry Garnet could be seen peering from the cover of the “rare and macabre” book about the Jesuit priest’s death.

“Claimed” and “thought to be” or not, that does sound rather rare and macabre. Full story here.