The masked manhunter known as Batman has had A LOT of adventures in his time. In fact, his monthly exploits in various DC Comics' publications have ensured that, over the last 74 years, barely 30 days have gone by without a new Batman story being published somewhere. Today, despite the fact that even Bruce Waynes youthful Ward Dick Grayson should now be claiming a pension, the Dark Knights monthly crime fighting schedule is busier than ever. So, how do DCs writers keep Batman stories interesting and fresh? Well, the Worlds Greatest Detective needs a constant stream of new cases to solve, of course. As well as that, Batman thrives on new enemies with new costumes, new manias and, of course, new merchandise potential. Every so often, a new villain is introduced who joins the ranks of the elite, or classic rogues, a villain who captures the lurid imaginations of the creators and the fanbase alike. Ras Al Ghul, (introduced in the 70s) was such a villain, ditto for Bane (introduced in the 90s). Latterly, Batman has faced funky new foes like Professor Pyg and The Court of Owls, both of whom I think its safe to say well be seeing again... ...But what happens when an otherwise promising villain slips through the cracks in continuity and vanishes completely? Allow me, gentle reader, to take you on a tour of the weird and wonderful, the transitional and the tangential, the odd and the odious, as I present 10 Batman villains who only appeared once...And who probably wont be appearing again.