rule 34 2018 animal genitalia anthro anus balls biped blue eyes body hair butt fluff cheek tuft cock worship countershading digital media artwork digital painting artwork fur glans gradient background grey background grey fur half length portrait happy trail keel kel looking at viewer looking down low angle view male male only mammal markings mej nude penis penis tip penis towards viewer pink background portrait precum presenting presenting penis reaching towards viewer sergal shaded sheath signature simple background sitting snout solo spreading tail between legs tan fur thick tail tuft vilous universe yellow markings 2687691