Jerome Valeska

"Why did you kill your mother Jerome?"

- James Gordon "Oh, you know how mothers are. She just... kept... pushing! And I'm like, "Fine mom. Be a whore. Be a drunken whore even. But don't be a nagging drunken whore... you know? Don't come yell at me to do the dishes, if you've been banging... a clown... in the NEXT ROOM! ...You know?" *maniacal laugh*"

- Jerome Valeska

Jerome Valeska is a minor antagonist in season 1 and the tertiary antagonist in season 2 of the Batman based TV show Gotham, appearing in the 16th episode "The Blind Fortune Teller". Jerome worked at the carnival with the Flying Graysons before killing his own mother due to her being a "nagging drunken whore". Jerome Valeska is supposedly/potentially the newly designed origin story of Batman's arch nemesis the Joker, at least in the Gotham series. He will be further explored in the second season.

Murdering his Mother
Jerome Valeska's mother was the snake dancer at the carnival, she was known for having sex with any male that worked at the carnival and she was also a hateful and mean woman to everyone around her (although the only proof of this came from Jerome itself so may not be true). Due to her life style and the way she treated him by always giving him orders Jerome hated her and wanted to see her suffer. Jerome finally snapped and hacked her to death with a hatchet. He later faked lack of knowledge of what happened to his mother and faked sadness for her death, although he was eventually caught by James Gordon, also revealing that his birth father was Cicero the blind fortune teller. When Jerome was questioned by James Gordon on why he killed her Jerome began to laugh as if it were all a big joke and told him she was a nagging whore that needed to die. He was later incarcerated at Arkham Asylum.

Escape at Arkham Asylum
Jerome, now serving time as a prisoner in Arkham befriends Barbara Kean, who was previously brainwashed to kill her parents by the now deceased Ogre. When newcomer inmate Zaardon dramatically introduces himself to the prisoners, he chokes up knockout gas and inmates Jerome, Barbara, Richard Sionis, Robert Greenwood, etc are broken out of Arkham orchestrated by Tabitha Galavan. The bunch are tied up and meet Theo Galavan, who inspires them to be part of a team of elite criminals. Sionis refuses and is killed by Tabitha, much to Jerome's joy.

Season 1

 * "The Blind Fortune Teller"

Season 2

 * "Damned If You Do"
 * "Knock, Knock"
 * "The Last Laugh"
 * "Strike Force"

Trivia

 * Jerome Valeska is the second named Joker adaptation after Jack Napier, he is also the youngest.
 * His implied future as the Joker was also advertised in promotional materials for his debut episode. For example, the trailer mentioned that the next villain in Gotham "is no joke" before cutting to Jerome Valeska cackling, and a Twitter post for viral marketing has a looped GIF of Jerome's laughter from the trailer with the tagline "Gotham's next villain is no laughing matter."
 * However when discussing season 2, show creator Bruno Heller described the Joker as being an ideology and not a man, so it is unclear if Jerome is the genuine Joker or somebody undertaking the identity.
 * The name Jerome probaly comes from Jerry Robinson co creator of the Joker.
 * Jerome Valeska worked at the same carnival as Batman's first sidekick Dick Grayson, the first Robin, before he was born.
 * Jerome Valeska is portrayed by Cameron Monaghan who is best known for his role as Ian Gallagher on the Showtime comedy-drama series Shameless. 
 * Jerome will return in the second season of Gotham in which the first half of the second season will be focused on the Joker's origin. Leaked on-set photographs depicts Jerome escaping Arkham Asylum and wearing a straight jacket and preparing to set a school bus with high school cheerleaders on board on fire.
 * During the Comic Con for 2015, Cameron Monaghan gatecrashed it in-character as Jerome making threats towards "Jim Gordon" (Ben McKenzie) asking about his pain tolerance. McKenzie in return got into character as Jim Gordon and told Jerome he will hunt him down.
 * Confirmed by David Mazouz, Jerome will meet Bruce Wayne in Season 2.
 * In a promo trailer he appears to have kidnapped Bruce.
 * Jerome is revealed to be 18-years old.
 * If the letters in his first and last name are switched around, Jerome Valeska can spell out Joker.