abs anthro anthrofied balls biceps big_muscles big_penis bigmaster black_fur black_nose boxers brown_background brown_fur canine chest_tuft claws dog erection fur green_eyes grin humanoid_penis male mammal muscles nevarrio nude pawpads paws pecs penis plain_background pose presenting rottweiler rufflecat sheath sitting smile solo spread_legs spreading toe_claws trunks_(clothing) tuft underwear