Black cat bone

A black cat bone is a type of lucky charm used in the magical tradition of hoodoo. It is thought to ensure a variety of positive effects, such as invisibility, good luck, protection from malevolent magic, rebirth after death, and romantic success.

...Got a black cat bone
got a mojo too,
I got John the Conqueror root,
I'm gonna mess with you...

—"Hoochie Coochie Man," Muddy Waters

The bone, anointed with Van Van oil, may be carried as a component of a mojo bag; alternatively, without the coating of oil, it is held in the charm-user's mouth.