This is a new video from Official Life Facts that lists 10 things you need to know about the Joker. The Joker is by far Batman's greatest foe and could very well be the best comic book villain of all time, depending on your point of view. First appearing in the debut issue of Batman (April 25, 1940), the clown prince of crime has terrorized Gotham City and Batman with absolutely no super powers. His popularity has led to four live-action portrayals, and appearances in video games, animated films and TV shows. Despite this popularity, you may not actually know everything there is to know about the Joker. Check out the video below.