Rule 34 Dev - 1boy animal_genitalia animal_penis anthro balls big_penis digitigrade equid equine equine_penis erection feral fingers genital_growth genitals growth hi_res hoof_hands hooved_fingers hooves horse human invalid_tag male male_only mammal mane mid_transformation nude penis penis_growth snout snout_growth solo sparks_99 transformation|6068845640