It's not well known that one of the elements Paul Naschy added to his screenplays was the occasional drawing to indicate specifics about how characters should look. His scripts were handwritten and his inclusion of these bits of art make me wish for the publication of facsimile copies of some - any - of them for fans to read. They would make it possible to get into the his head to understand more of his creative process or how his ideas grew from page to screen.
Here is a drawing from one of his Waldemar Daninsky El Hombre Lobo film scripts.
And here is a color rendition of his vision of Doctor Jekyll from DR. JEKYLL AND THE WEREWOLF (1972).