rule 34 animal genitalia animal penis anthro balls big balls black nose canid canine canine penis detached sheath flaccid flexible fox fully sheathed fur genitals grey body hair hi res male mammal muscular muscular anthro muscular male nipples nude one leg up penis pirin apex platinum fox raised leg red fox scar sheath simple background solo splits spread legs spreading standing vein veiny balls vertical splits yuri degtyarev pirin apex 4353986