Rule 34 Dev - animal_genitalia animal_penis anthro balls big_penis black_body black_fur canine_genitalia canine_penis close-up crotch_shot erection fur genitals glans knot male navel nude penis presenting sheath simple_background solo spread_legs spreading urethra vein white_background anakuro canid canine canis mammal wolf 2013 digital_media_(artwork) sketch|1666892780