"The Witcher" is a sprawling high fantasy full of magic, knights, and horrendous murder beasts. Somewhere between "Game of Thrones" and "The Lord of the Rings," the novels (and, by extension, the videos games, and the Netflix series) feature a vicious armada of craven cryptids who would like nothing more to chow down on a few locals, if given the chance. We're talking Leshy and Djinn and Basilisks (they're nothing like the "Harry Potter" snake, sorry) and Ghouls and Bruxa and all kinds of...