This song was written by Willie Dixon and recorded in 1954. It is taken from Muddy Waters on Chess 1951-1959, Vol. 2 (Vogue 600059).

I got a black cat bone
I got a mojo too
I got the Johnny Concheroo
I'm gonna mess with you
I'm gonna make you girls
Lead me by my hand
Then the world will know
The hoochie coochie man
But you know I'm him
Everybody knows I'm him
Oh you know I'm the hoochie coochie man
Everybody knows I'm him

On the seventh hours
On the seventh day
On the seventh month
The seven doctors say
He was born for good luck
And that you'll see
I got seven hundred dollars
Don't you mess with me
But you know I'm him
Everybody knows I'm him
Well you know I'm the hoochie coochie man
Everybody knows I'm him

This song contains some terms that can be related to Voodoo. Some have other meanings too, but the importance of Voodoo and hoodoo magic is dominating the song. A hoochie coochie man is someone who preaches voodoo. Hoochie coochie men are also conjure 'doctors', male or female.
Black cat bone is a hoodoo term, which is used as good luck charm and especially to bring back the wayward lover. Costly and valued, its scarcity was largely due to the elaborate ceremony, which was required for its preparation. Every black cat has within its body one bone that will either grant the owner invisibility or can be used to bring back a lost lover. To secure this bone, a black cat must be thrown alive into a kettle of boiling water at midnight. The animal dies in agony, and the practitioner boils the carcass until the meat falls off the bones. Some say that the special bone will be the top one left when the water boils away. Others say that it can only be found by placing each bone in turn beneath the tongue while an assistant stands by to notify the practitioner that he has become invisible. And, still others swear that if all the bones are thrown into a stream running north (uncommon in most of North America), the desired bone will be one that floats on the water and heads south. Once found, the black cat bone is carried in a mojo bag and anointed with Van Oil in order to bring back a lost lover. The oil or fat of the cat is bottled for use as a candle dressing and for anointing gambler's charms.
First, the term mojo refers to a magic spell, hex, charm, amulet or a conjuring object. Secondly, a mojo may also be the staple amulet of African-American hoodoo practice, a flannel bag containing one or more magical items. They were made with great care and contained personal fragments and natural objects: hair from the armpits or pubic region, fingernail pairings, pieces of skin were considered especially effective in love charms, as were fragments of underclothing, of a menstrual cloth and other closely personal effects. Combined with parts of night creatures, bats or toads, and with ashes and feathers from sources selected for a symbolic significance relative to the purpose for which they had been prepared. They were all tied up into small conjure bags or put into an innocuous-looking receptacle and either carried to exert their power upon the victim when contact was made with him or buried beneath his doorstep, hidden in his bed or hearth. The word is thought to be a corruption of the English word 'magic.' When Muddy Waters sings in "Hoochie Coochie Man" that he has "a John(ny) the Choncheroe/Conqueroo," he means a (High) John the Conqueror root - the hard, woody tuber of Ipomoea jalapa, a relative of the common sweet potato. In magical practice, the root is not ingested, probably because it is an extremely powerful laxative. Instead it is used whole, carried on the person as a pocket piece or as an ingredient in a mojo bag, especially one designed to draw money, bring luck at games of chance, or enhance personal sexual power.

So please keep in mind as you encounter a zombie rising from his tomb, or watch a painted witch doctor stabbing pins into a doll, that most of these movies are certainly not an accurate reflection of the Voodoo religion!