The head of a viper talisman is an old charm with roots in the Arab world. It was known and practiced in Western European magic and found it's way through the Cyprianic tradition into Brazilian and Latin American folk magic.
The most common form of the charm - shown in the photo, translated from O Grande Livro de São Cypriano (The Great Book of Saint Cyprian) simply calls for the head to be sealed into a cane, umbrella, or horn that one carries and petitioned with faith for assistance.
These are genuine dried rattlesnake heads. All rattlesnakes are pit vipers, of the family Viperidae.
Very powerful items always obtained from Holy mountain.