An important ritual tool in the practice of Voodoo or Voudoun. It is a sacred rattle used in various rites. Typically it made of a coconut with beads (traditionally made of snake vertebrae) strung around it and placed on a stick. Rather than being shaken, one hand holds the beads while the other hand is used to twist the stick rhythmically back and forth, resulting in the beads scraping over the rough surface of the coconut and producing its sound. Sometimes they are brightly colored.

The Asson is a symbol of a Voudoun priest (Houngan) or Priestess (Mambo). To be "given the asson" is an expression meaning that a person has been raised to the priesthood.