rule 34 2016 4 toes animal genitalia anthro balls black balls black fur black nose blue eyes blue fur blue hair brothers canine chest tuft claws color swatch duo facial markings fully sheathed fur hair inner ear fluff kneeling looking at viewer male mammal markings model sheet multicolored fur muzz nude open mouth pinup pose purple background red eyes red fur red hair sheath sibling simple background smile toe claws toes tuft twins two tone fur watermark wolf 2176736