We have a general policy of PG-13, and also reserve the right to reject any content we don't feel is a good match for the platform. While monsters are often meant to be wild and sometimes disgusting, I'd have trouble signing off on human centipede inspired art unless you found some creative ways to make it more monstery awesome and less "huh.." Excited to see your pack and all the other fun scaries in it :) Thanks for the question!