rule 34 2016 absurd res all fours animal genitalia animal penis anthro athletic balls belly big penis black hair blue background blue hair bondage bondage gear bound digital media artwork donkey equine equine penis erection fur gloves marking hair harness hi res hooves cock huge cock hybrid penis kihu kneeling looking at viewer male male only mammal manly markings mature male medial ring multicolored hair nipples nude penis pose purple eyes raised tail relaxing side view simple background smile socks marking solo tail tuft teeth thick penis tuft two tone hair vein veiny penis zigg 2504710