Riddler (Batman Forever)

The Riddler, AKA Edward Nigma, is one of the main antagonists in the movie; Batman Forever. He teams up with Two-Face so he can get rich, become Gotham's cleverest carbon based life-form, get his revenge on the Bruce Wayne, and figure tout the identity of Batman.

History
Edward Nygma starts out as an employee researcher at Wayne Enterprises who is obsessed with Bruce Wayne. Nigma wanted to use Wayne to test out his invention which was capable of beaming a TV signal into someone's brain. But Bruce rejects his invention and tells Nygma that it 'raises too many questions'. Angered by Bruce's rejection, he goes to his supervisor and tests it on him, getting fired in the process. After getting fired, Nygma started to secretly test Bruce by leaving him a long line of riddles throughout the film.

Becoming the Riddler
Nygma was so satisfied with the work of Two-Face on live television at a circus, he took his own take on the criminal underworld as the mastermind known as the Riddler. Forming an alliance with Two-Face, they work together to expose and kill Batman. But the Riddler also had the intention to put his invention (which was rejected earlier in the film) on every TV in Gotham and become 'Gotham's cleverest carbon-based life form' to outwit Bruce Wayne. But his true intention was to use his invention to steal the people of Gotham's quotient of intelligence into his own brain.

At a business party, Nygma uses his now-successful invention to find out Bruce Wayne's secret identity as the Batman. After a deadly attack by Two-Face, they together watch the things that Wayne 'has in his head' which meant that he was Batman.

Afterwards, Riddler and Two-Face invade Wayne Manor only to let Riddler to destroy the Batcave in the process. When Two-Face made his move to kill Bruce, he told him as he placed his final riddle on the doorstep, 'You won't learn nothing.' And they kidnap Dr. Chase Meridian to lure Batman and his new sidekick Robin to their lair.

Using a battleship like machine while playing a life and death game with Two-Face, Riddler was able to destroy Batman's Batwing and send his goons after him and Robin only to lift up his lair.

Riddler's Downfall
Finally coming face-to-face with Batman, Riddler claims that using his invention, he will use it to go to countless TV's across the globe that will feed him 'credit card numbers, bank codes, sexual fantasies and little white lies' into his brain. He then attempts to test Batman by dropping either Dr. Meridian or Robin into their grave which is underwater. He is defeated when Batman uses a Batarang to destroy his big replica of his invention thus destroying his lair. He is then afterwards taken to Arkham Asylum. Dr. Burton calls Dr. Meridian and tells her that the Riddler would shout that he'd know the true identity of Batman. Dr. Meridian asks who Batman is, but Edward says that she must say "please". When she asks with "please" who Batman is, the Riddler appears saying: "I am Batman". He then starts moving his arms like a flying bat and laughs manically.

Trivia

 * The Riddler is portrayed by Jim Carrey
 * It's unknown if The Riddler's real name is Edward Nashton as in the comics.