There have been some libraries to download somewhere in the wiki, as the wiki is about being reorganized I can't find them now. From my download of arch blocks I have zipped persons. I hope there are no license issues with that, otherwise LordofBikes has to ban me. Unzip into your library directory (librecad/recources/library) or define a path in Options/Application Preferences/Path or just open a file and copy the person into your own drawing.
persons.zip