A dangerous and unpredictable master villain, the Joker is the mortal enemy of Batman. The Batman Family has long-suffered at the Joker's hands. The Joker killed the second Robin (Jason Todd) beating him to near-death before leaving him to die in an explosion. He maimed Barbara Gordon (aka Oracle), shooting her through the spine ending her career at Batgirl, then photographing her bleeding body in an attempt to drive Commissioner Gordon insane.
The Joker is adept at chemistry, including chemical weapons (Joker Venom) and utilises a range of deadly conventional and joke-prop weapons which, combined with his maniacal master-intellect, makes him a deadly foe.< LESS