rule 34 2021 animal genitalia animal penis anthro anus ass ass up backsack balls black body black fur brown body brown fur canid canine canine penis canis detailed background digital media artwork digitigrade dobermann domestic fur genitals hand behind head inside jack o pose looking at viewer male mammal meme multicolored body multicolored fur muscular muscular anthro muscular male mystikfox61 nipples open mouth open smile pawpads paws penis penis tip pink pawpads pinscher pose presenting presenting anus presenting hindquarters sheath smile solo stub tail tailwag tongue tongue out two tone body two tone fur window 5126683