Rule 34 Dev - 2021 animal_genitalia animal_penis anthro balls black_balls black_eyes black_hair black_mane black_nipples buckskin casual_nudity equid equine equine_genitalia equine_penis erection fur genitals hair hi_res horse male mammal mane mediterranean navel nipples nude penis penis_shadow sheath solo staff storm_engineer tan_body tan_fur|8294056608