The Scarecrow

The Scarecrow, also known as Jonathan Crane is an enemy of Batman and was the first enemy the Justice League ever faced, in fact his possession of the Book of Eternity is what caused them to unite. He is obsessed with fear, and under the persona of the Scarecrow he hopes to spread fear. He has been portrayed by Jack Hillebrecht in all of his appearances. The intent was to recast the role for his return in LEGO Batman: Adventures in Gotham City but Hillebrecht decided to continue playing the role to keep the character's return a secret.

Background
At some point in his career, he was sent to Arkham Asylum after being captured by Batman. He obtained the Book of Eternity from "Knuckles" Konger and took control of his gang. He created Bizarro Batman and intended to build a superweapon to spread fear throughout the city, and released a fear entity known as Parallax to further fuel his machine, however, Parallax had his own plans. Parallax took over Crane's Body and they mutated into a massive serpent. It swallowed Batman and Superman, who tried to blow up Crane from the inside. While not killing the serpent, it did seriously injure it, so Parallax abandoned Crane was absorbed back into a deep part of the Phantom Zone from where he was trapped. The newly formed Justice League confronted Crane, who grabbed the book and attempted to unleash its full power, however, his mortal body could not handle such power, he himself was absorbed into the phantom zone.

Scarecrow was trapped in the Phantom Zone for over a year, and on April 5, 2014, when The Battle of Gotham City occurred, General Zod opened thousands of portals from the Phantom Zone to Gotham City, to allow Parallax's demon army to come to Earth. However, Crane managed to get through one of these portals and escaped back to Earth. He went into hiding for about a year until he decided to team up with Zod, who had released him a year earlier, but were quickly stopped by Batman and Superman.

Once back in Arkham, he was offered by The Joker a place in his newest plot, and accepted. Several months later, there was a mass breakout leading to Crane's freedom. The escapees: The Joker, The Penguin, Killer Croc, Bane, Man-Bat, Mr. Freeze and Crane himself then started a riot at town hall, killing hundreds and kidnapping Alfred Pennyworth. Soon after, the perpetrators of these crimes were all arrested, including the Scarecrow. He is currently undergoing rehabilitation at Arkham Asylum.

Trivia

 * The reason that The Scarecrow was taken into the phantom zone was that he was set to be the main villain of Intergalactic Crisis 2 a project that was ultimately cancelled due to Ryan's withdrawal from JTH Studios as well as several other factors. The ending of LEGO Justice League was intended to set up this project, and with its cancellation, left the Scarecrow out of the series. This is the only purpose of Episode 3 of LEGO Batman: Adventures in Gotham City, to bring the Scarecrow back into the story.