The villainous League of Shadows founder was most notably played on the big screen by Liam Neeson in Christopher Nolan's Batman Begins. MTV recently asked the actor if Warner Bros. or The CW Network have approached him to play the villain on Arrow. While he hasn't been asked to reprise the role yet, the actor did say he would play him again in a heartbeat.
"No, I haven't (been approached), I haven't at all. I would, in a heartbeat, if it came my way, yeah. Very much so."
Of course, Warner Bros. and The CW Network have been keeping their movie and TV superhero universes separate, so it doesn't seem likely that Liam Neeson will return to play Ra's. However, the actor did offer some advice to the actor who will go on to portray the villain.
"They have to believe in their philosophy. Ra's al Ghul absolutely believed what he was doing was ultimately saving civilization, and it was quite a good argument he comes up with. Throughout the ages this fraternity, that brought the plague to wipe out a section of mankind because it needed to be regenerated again. Very dangerous, but you have to believe it."