Here's a good site on this sort of thing:
click here
BTW: I have also heard pf the term "mojo" or "mojo hand" used to mean a monkey's (or similiar) hand/paw used as a talisman, usually worn on a necklace of beads, etc.
There's a picture of Johnny Shines wearing one on one of his album covers. There was also a tribute to Muddy Waters show shot for public TV in Chicago in which Dr. John presents Muddy Waters with one as a gift.
Any further info?
-Chris