Therianthropy, referring to animal-human transformation, is a controversial term, employed by some mythic scholars and not others. Its origins have been variously dated to the sixteenth, nineteenth, and twentieth centuries.
Boria Sax, The Serpent and the Swan: The Animal Bride in Folklore and Literature(Blacksburg, Va.: McDonald and Woodward, 1998.)
Translated by Liisa Rantalaiho