Real world article
(written from a production point of view)
Voodoo, a Human religion in reality, was referenced in the final draft script of the Star Trek: The Original Series first season episode "Charlie X". In the script, Spock satirically asked Doctor Leonard McCoy if he wanted him to arrange for McCoy to give Charles Evans, who McCoy had just been ordered to mentor, some "voodoo and superstition lessons." To that remark, McCoy jokingly replied, "You can if he provides his own chicken's teeth and penguin feathers,".