Rule 34 Dev - animal_genitalia animal_penis anthro anus apple-faced ass backsack balls biped dock_(anatomy) equid equine equine_genitalia equine_penis erection flared_penis fur genitals hay hi_res hooves horse luckystallion13 male mammal medial_ring penis perineal_raphe perineum raphe_(anatomy) solo tail vein veiny_penis|12948107984