4_toes all_fours animal_genitalia balls barefoot blue_nails butt canine canine_penis chain claws collar cyan_pawpads cyan_penis digitigrade ear_piercing erection grey_background hindpaw knot looking_at_viewer looking_back male mammal markings nude pawpads paws penis piercing plain_background presenting presenting_hindquarters raised_tail redic-nomad smile socks_(marking) soles solo toes wolf