Wade got it from Peter Freuchen

Edit: Holy shit Wade Davis, from Wikipedia

In 1983, Davis first advanced his hypothesis that tetrodotoxin (TTX) poisoning could explain the existence of Haitian zombies.[10] This idea has been controversial and his 1985 follow-up book (The Serpent and the Rainbow) elaborating upon this claim has been criticized as containing scientific inaccuracies.[11] One is the suggestion Haitian witchdoctors can keep “zombies” in a state of pharmacologically induced trance for many years.[12] As part of his Haitian investigations, Davis commissioned the exhumation of a recently buried child.[13][14] (Dead human tissue is supposed to be a part of the “zombie powder” used by witchdoctors to produce zombies.) This has been criticized as a breach of ethics.[12][15]