It’s more like the designs were by H.R. Giger, whose design principle was “yeah but what if it was a vagina and/or penis?”

EDIT: Not quite right. Giger did designs for Jodorowsky’s failed Dune project which Lynch took over. I would still say there some elements in the movie that look quite Giger-y. But his sandworm looked like this: https://www.reddit.com/r/dune/comments/qqavbd/here_is_hr_gigers_design_for_the_sandworms_which/