The second half of Season Four of Gotham is already in full swing, promising even more twists and turns as we follow young Bruce Wayne on his path toward becoming Batman. After the mid-season finale in December, the series returned in March following the aftermath of the Tetch Virus and Oswald's attempt to regain control of the city. So far the season has revisited baddies such as the sinister Scarecrow and a newly blossomed Ivy as well as offering teasing glimpses of returning villains like Ra's Al Ghul and Jerome. The first half of the season drew upon Batman: The Long Halloween while the second half will reference Batman: Year One and Batman: No Man's Land.

Considered an in-depth, yet alternative origin story of how the Dark Knight came to be, Gotham also explores the backstories of important characters, both good and evil, behind the creation of Batman. While many of the younger stars of the show are enjoying their breakout roles as the iconic members of the Caped Crusader's crew, such as David Mazouz as Bruce Wayne and Camren Bicondova as Selina Kyle, some of the older generation got their head-start elsewhere. Below, CBR has revealed some of the most surprising roles behind 15 Gotham actors.

15 BEN MCKENZIE, THE O.C

On Gotham, McKenzie plays the newly appointed Captain Jim Gordon. Despite his determination to bring justice to Gotham, Gordon has walked a very thin line between right and wrong when trying to rid the city of evil. In Season 4, we find him forming a partnership with Sophia Falcone, daughter of Carmine Falcone, to end Oswald's use of illegal "licenses of misconduct."

Fans of teen drama series will recognize McKenzie from his role on The O.C as Ryan Atwood. As the brooding yet compassionate main character of the show, McKenzie charmed his way into the heart of "girl-next-door" Marissa Cooper, leading to an on-again, off-again romance. The show was considered one of the most popular drama series during 2003-2004 and became a pop culture phenomenon. McKenzie received the role, originally offered to Chad Michael Murray, because "he inhabited the character" better than casting director Patrick Rush could have imagined.

14 MORENA BACCARIN, THE FLASH

It appears Morena Baccarrin has been making the rounds in the superhero universe. On Gotham, Baccarin plays Leslie Thompkins, former medical examiner of the GCPD turned ruthless Queen of the Narrows. The actress will also be returning in Deadpool 2 as the foul-mouthed assassin's girlfriend Vanessa. She has also appeared in television series such as Firefly, Stargate SG-1, and V.

However, fans of the CW hit The Flash may have also recognized the actress as the voice of Gideon, an AI used by Eobard Thawne known as The Reverse-Flash. It is later revealed in the series that Gideon was created by Barry Allen sometime in the future. Baccarin's voice talents can also be heard in Justice League Animated as Dinah Lance / Black Canary and in both Son of Batman and Batman: Bad Blood as Talia Al Ghul.

13 DONAL LOGUE, LITTLE WOMEN

As Harvey Bullock, Logue is a jaded member of the GCPD who isn't afraid to get his hands dirty when it comes to bringing justice to the criminal underworld of Gotham. Despite his gruff exterior, Bullock is loyal to those he finds worthy of his trust and is willing to lay down his life if needed. In Season Four, Bullock is the acting Captain of the police force until he is replaced by Jim Gordon after a botched takedown of Professor Pyg leads to the death of fellow officers.

Logue is known for portraying tough characters and has appeared in other superhero franchises such as the first Blade film and Ghost-Rider alongside Nicolas Cage. In 1994, Logue portrayed Jacob Mayer in the film Little Women based on the famous novel. The film received positive reviews, mainly due to its talented female cast and intriguing story-telling.

12 MICHAEL CHIKLIS, THE THREE STOOGES

When you think Michael Chiklis, your first thought is probably his portrayal of Ben Grimm / The Thing in the 2005 and 2007 Fantastic Four films or as Vic Mackey on The Shield. Fans of the American Horror Story phenomenon will recognize him from Freak Show as the strong-man Dell Toledo. In 2000, Chiklis portrayed Jerome "Curly" Howard in The Three Stooges, a television biography of the iconic comedy trio. The movie attempted to show the bitter reality of the group behind their hilarious shenanigans.

On Gotham, Chiklis played Captain Nathaniel Barnes, a no-nonsense officer who is determined to cleanse the city of all forms of corruption. After being exposed to Alice Tetch's corrupted blood, he takes matters into his own hands and becomes "The Executioner," delivering brutal and often fatal punishment to those he finds deserving without remorse.

11 RICHARD KIND, CAROL & COMPANY

Recognized as one of the most frequently used character voices in various Pixar films, Richard Kind's acting career spans many years and genres. He has made appearances on shows like Spin City, Scrubs, Mad About You, and performed on stage in Broadways plays such as "The Producers" and "Sly Fox." His first big television break however was in 1990 as a member of Carol Burnett's sketch group on Carol & Company. Unlike her previous comedy shows, Carol & Company was an anthology series which had the members perform different half-hour comedy skits.

As former long-term Mayor Aubrey James, the actor portrayed a deeply corrupted political figure under the sway of criminal mob boss Carmine Falcone and the mysterious Court of Owls. Despite his arrogance, James was a complete coward when it came to confronting those who opposed his authority, especially Jim Gordon and Oswald Cobblepot.

10 NICHOLAS D'AGOSTO, HEROES

As Harvey Dent, D'Agosto got to indulge in his darker side leftover from his time filming Final Destination 5. Though we have yet to see his full transformation into Two-Face, the actor did show brief glimpses of the sinister personality behind his mild-mannered persona as District Attorney of Gotham City. Dent was presented as one of the few non-corrupt lawyers in the city and an ally to Gordon but was shown to grow aggressive when confronting criminals.

D'Agosto has made brief appearances on various television series such as Supernatural, ER, and The Office. In 2007, he played West Rosen, boyfriend to Claire Bennet, on Heroes. Similar to the many super-powered individuals on the show, it's revealed early in the first season that Rosen has the ability to fly. His relationship with Bennet proves challenging due to her overprotective father who is secretly gathering research on other enhanced beings.

9 JAMES REMAR, THE WARRIORS

Before he played Frank Gordon, uncle to Jim and former member of the Ruling Council of The Court of Owls, James Remar starred in the cult film The Warriors. As Ajax, Remar was a rambunctious and cocky member of the Coney Island gang. Despite his rough attitude and lustful behavior, he proved to be fiercely loyal to his group and was the toughest member. In the film, his most prominent performance is during the fight with the Baseball Furies, when he tries to assault an undercover police officer after being ambushed by the rival rang.

On Gotham, Remar's character is manipulative, trying to lure his nephew into joining the Court's plan to cleanse the city of any threats to their power. It is revealed that Frank, desperate to keep the Court's existence a secret, ordered a hit on his brother Peter who tried to expose the dark society. Instead of following his superior's orders to kill Jim, Frank commits suicide, telling his nephew to play along with the Court's plan.

8 CLARE FOLEY, SINISTER

Before undergoing a dramatic transformation (and being recast twice), Ivy Pepper was played by young Clare Foley. The pre-pubescent Poison Ivy was orphaned after the murder of her father and displayed a preference for plants over people. Despite her introverted nature, Ivy displayed a sarcastic wit which develops into a fiery seduction technique as she rapidly matures during each season's progression. The second half of this new season showed a newly-blossomed Ivy, eerily reminiscent to Uma Thurman's "Hell, I am Mother Nature" debut in the 1997 Batman film, played by Peyton List.

In 2012, Foley played the daughter of true crime writer Ellison Oswalt in the horror film Sinister. She's an artistic child who becomes the latest victim of the supernatural force possessing children, leading them to brutally murder their family members. The film received fairly decent reviews, many praising its deeply traumatic storyline and terrifying thrill-factor.

7 NATHAN DARROW, PREACHER

Season 2 of Gotham introduced cryogenicist engineer Victor Fries attempting to successfully create a freezing technology that would save the life of his terminally-ill wife Nora. In his desperation, he became the criminal Mr. Freeze, testing his experiments on the citizens of Gotham. After his wife, saddened by what her husband has become, commits suicide, Fries tries to do the same by turning his own chemicals on himself. In the process, his DNA becomes altered and he's unable to survive temperatures of more than -50 degrees.

Portrayed by Nathan Darrow, Fries suffered incredible emotional distress that caused him to become overwhelmed with feelings of guilt. On Preacher, these same feelings are suffered by Jesse Custer after witnessing his father's murder. As John Custer, Darrow plays a devout believer in God who tries to set his son down the path of righteousness by teaching him to be a kinder, stronger person.

6 KRISTEN HAGAR, BEING HUMAN (SYFY)

In 2011, Syfy debuted its version of the BBC supernatural drama series Being Human. Similar to the original, the show followed the lives of a werewolf, vampire, and ghost who attempt to have normal existences among humans. Kristen Hagar played Nora Sergeant, girlfriend and later wife of werewolf Josh Levison. Toward the end of the first season, Nora's scratched by Josh and becomes infected with his curse and in Season 4, it's revealed she is pregnant with a purebred.

As Nora Fries, Hagar showed a strong dedication to her husband Victor but was horrified to learn what he had become in his desire to save her from an incurable fate. After successfully learning how to revive his frozen prey, Victor attempts to use his discovery to help Nora. While he is distracted, she switches the cartridges in the freezing gun, knowingly killing herself in the process.

5 JAMES FRAIN, TRUE BLOOD

Created as an original character for the series, Frain played Theo Galavan who came to Gotham to seek revenge against the Wayne family and claim power over the city. Galavan presenting himself as a selfless individual, using his cunning nature to deceive those around him into doing his bidding. He becomes mentor to the sadistic MANIAX and uses their illegal antics as a means to fuel his desire to become mayor of a city in need of saving.

On the third season of True Blood, Frain plays "hot mess" vampire Franklin Mott. Known or his lack of respect and tendency to become easily jealous, Mott has a horrible track record when it comes to women. He also holds no loyalty or regard for the vampire hierarchy and works exclusively for Russell Edgington, the vampire king of Mississippi.

4 JESSICA LUCAS, CLOVERFIELD

Before donning a leather wardrobe and cracking a whip as Tabitha Galavan, Jessica Lucas fell victim to an alien attack in Cloverfield. As Lily Ford, Lucas was a member of a group of New Yorkers who attempt to survive an assault from an unknown creature from space. The film itself was shrouded in secrecy, having multiple titles and only a handful of teaser trailers. Receiving generally positive reviews, two sequels were later made in 2016 and 2018 and a fourth film is set be released later this year.

As Tabitha aka Tigress, Lucas is the headstrong sister of Theo Galavan who allies herself with Barbara Kean and Butch Gilzean following her sibling's death. Her character is a sadist, receiving great pleasure from mistreating and torturing others. Unlike Theo, her motives are based on impulse rather than calculated thought.

3 MARINA BENEDICT, FLESH AND BONE

Benedict made her limited debut on Gotham as the feisty Cherry, a fight club owner in the rough and tough Narrows. It's revealed that she is secretly working for Oswald Cobblepot as his spy and is killed by Barbara Kean. She is succeeded by Leslie Thompkins as the new "Queen of the Narrows."

On Flesh and Bone, she played Toni Cannava, the new choreographer of the American Ballet Company. The Starz drama miniseries explored both the glamor and cruelty of the ballet world, following a troubled rising dancer meant to replace an aging prima ballerina. The eight episode series received mixed reviews despite being considered by some to be a very compelling show with a cast of professional dancers; likened to a more authentic version of Black Swan.

2 MICHAEL CERVERIS, THE VAMPIRE'S ASSISTANT

One of the most deeply controversial villains on Gotham, second to Jerome, is Michael Cerveris' Professor Pyg. Hiding his real identity, Lazlo Valentin is a contract killer and assassin known for impersonating serial killers. He is hired by Sophia Falcone to end Oswald's control over the GCPD, targeting corrupt officers and arranging their corpses in gratuitous poses featuring decapitated pig heads. He possessed a high intelligence but a deeply fragile ego, ultimately meeting his death at the end of Jim Gordon's gun.

Known for his roles on Fame, Fringe, and The Good Wife, Cerveris appeared in The Vampire's Assistant, based on the first book of the "Vampire Blood" trilogy. As Mr. Tiny, his character is a trickster who loves to meddle in the affairs of both the living and undead. An appreciator of a good fight, he turns the main character's best friend against him.

1 ALEXANDER SIDDIG, STAR TREK DEEP SPACE NINE

Siddig was given the pleasure of playing one of the most iconic villains of the Batman universe. As Ra's al Ghul, the actor portrayed a mysterious and sinister character who foresaw Bruce's future as the savior of Gotham. He preys upon the young boy's sensitive mind, driving him toward the belief that the corrupt city needs to be harshly purged of evil. He also develops a close partnership with Barbara Kean, using her for a purpose that remains to be fully seen.

On Star Trek: Deep Space Nine, he plays Julian Bashir who serves as Chief Medical Officer. Due to his genetic enhancements, Bashir has a superior intellect compared to normal humans. While on Deep Space 9, he befriends Elim Garak, a Cardassian tailor and develops a strong bond with Miles O'Brien. He also has numerous romantic relationships with fellow crew mates.