Faites chier la vache !
Although the term "fetcher" (understood as to fetch, to bring in) is widely recognized today in the tradition, you have to understand that it is a deformation of the original Old French.
As it is clear in the historical document, the French person orders "Faites chier la vache !", which would translate literally as "Make the cow crap !"
However "faire chier" β which nowadays means "to annoy, to bother" severely, in colloquial French β used to mean "yeet" up until XVth century Old French.
Fais chier Grand-mΓ©re !
(Yeet Grandma !)
Hence the command "Faites chier la vache !" β Yeet the cow ! β, which became "Fetchez la vache !" with the evolution of language.
Or at least it is what I believed the movie said, until I created my Masto account