Ra's al Ghul is by far the greatest Batman villain barring The Joker. Created by Dennis ONeil and Neal Adams and introduced in Batman #232 (1971), Ra's al Ghul is a 700-year-old eco-terrorist with close personal ties to Batman. As The Demon Head a title given to the leader of The League of Assassins Ra's al Ghul is one of the most powerful and influential villains in not only the Bat-verse but also the entire DC Universe. Kept alive for hundreds of years by the Lazarus Pit, which drives the user crazy every time its used, Ra's al Ghuls mad vision is to see the world burn in a purging fire. He seeks to perfect the world by destroying society and rebuilding it into a utopia. Unlike many of Batmans foes, Ra's was able to deduce that Bruce Wayne and Batman are one-in-the-same. After his daughter, Talia, falls in love with Batman, Ra's not only uncovers Batmans secret identity but also hatches an elaborate plan to test Batman as a potential heir to the al Ghul legacy. Upon discovering this plan, Batman rejects Ra's al Ghuls proposal, as he is appalled by Ra's al Ghuls genocidal vision. Despite their differences, Ra's al Ghuls and Batman share a number of traits. Both are excellent in hand-to-hand combat; both are filthy rich; and both have genius level intelligence. Even Ra's al Ghuls vision is simply a hyperbolized version of Batmans crusade against crime. In many ways Ra's is Batmans equal, and considering that Ra's has access to a Lazarus Pit and hes the grandfather of Bruces son/Robin (Damian Wayne), Ra's al Ghul will quite literally forever be intertwined in Batmans life.