The Riddler, also known as Edward Nigma, is a supervillain and one of Batman's most notorious enemies. He is often referred to as Batman's NEMESIS, or archenemy, due to their long-standing rivalry. The Riddler is a criminal mastermind who uses his intellect and riddles to challenge Batman and other members of the Gotham City Police Department. He is also known as Batman's FOE, as they are constantly at odds with each other.