Why the Joker from Gotham looks so familiar

It's unclear if Cameron Monaghan is actually playing the Joker on FOX's DC Comics series Gotham, or if his character on this Batman prequel is just eerily similar to the bad guy we all know and love to hate. If he's not, then his character, Jerome Valeska, is sure giving a convincing performance as the would-be Clown Prince of Crime. In either case, seeing Monaghan on the series must have left some audience members questioning where they've seen that actor before. Here are a few of his most recognizable roles.

Malcolm in the Middle (2004 - 2005)

One of Monaghan's earliest major roles came as Chad on the FOX comedy Malcolm in the Middle, in which he made his debut in the season five episode "Dewey's Special Class" and carried out a six-episode, recurring story arc on the series until the end of its sixth season. As with the rest of Dewey Wilkerson's friends, Chad was a Busey, but a particularly belligerent one. He frequently wore signs on the front and back of his clothes with hand-written warnings and other generalized statements. For instance, in his first appearance, he wore a sign saying, "Don't Touch, Bites." Just in case people didn't read the sign—or perhaps didn't care enough—he wore another sign on his back, saying, "Don't Ignore the Sign." He also had the habit of taping boxing gloves and oven mitts to his hands, and that's aside from the fact that he thought he had four doppelgangers wandering around.

Guest roles (2005 - present)

After finishing up his stint on Malcolm in the Middle, Cameron appeared to get the itch for more television roles. Later that year, he guest-starred on the science fiction drama Threshold as Josh Foster; over the next few years, he played Poi & Ping on Avatar: The Last Airbender, Jeffrey Charles on Criminal Minds, and Andy on Shorty McShorts' Shorts. It wasn't until 2009 that he really started to find his groove, however—that year, he took on seven guest-starring roles in a list of shows that included Monk, Fringe, Numb3rs, The Mentalist, and even James Gunn's PG Porn. Although his career has taken off since then, Monaghan continues to take the occasional small role on TV shows such as Law & Order: SVU and Son of Zorn.

Ned's Declassified School Survival Guide (2005 - 2006)

Along with snagging guest appearances on a growing list of shows, Monaghan landed a brief, recurring role on Nickelodeon's Ned's Declassified School Survival Guide, which aired for three seasons in the mid-2000s and followed a trio of middle school students during the seventh and eighth grades. One of the students, Ned Bigby, comes up with new tips for his survival guide that helps him and his friends get a handle on everyday life. Monaghan made his appearances in the final season, playing Palmer Noid, a student known as the kid who'd steal your pants, as if that's something you want to be known as during middle school—of all times.

Click (2006)

Before making his way to television, Monaghan took a stab at movies, but it wasn't until 2006 that he starred in a major production: the Adam Sandler comedy Click, in which he played Sandler's pesky ten-year-old neighbor Kevin O'Doyle, who has a tendency to boast about how much greater his father's stuff is compared to Sandler's Michael Newman. Although it was a small role, Monaghan did an excellent job playing the antagonizing next-door neighbor, whose purpose in the story is to push the main character over the edge, psychologically—little by little, day by day. The film garnered less-than-stellar reviews, with critics citing its failure "to produce the necessary laughs." However, it still managed to pull in a substantial sum at the worldwide box office, making it Monaghan's highest-grossing movie to date.

The Santa Claus 3: The Escape Claus

A few months after Click hit theaters, Monaghan was back on the big screen in Disney's The Santa Clause 3: The Escape Clause. Tim Allen reprised his role as Santa Claus (and Scott Calvin) in the franchise's third installment, returning along with the majority of the series' supporting cast. Among the newcomers was Martin Short, who played the antagonist Jack Frost, and Monaghan, whose brief appearance in the film found him arresting Jack Frost in the North Pole.

Prom (2011)

After his stint working for Santa Claus, Monaghan never left the big screen. He kept starring in smaller movies, like Running, Safe Harbor, and Another Harvest Moon, but people may recognize him from Joe Nussbaum's teen rom-com Prom. Monaghan co-starred alongside the movie's main stars Aimee Teegarden and Thomas McDonnell in the Disney-produced movie, playing Corey Doyle, the best friend of Nolan Sotillo's Lucas Arnaz, who is billed as being a shy audiophile that has a crush on Campbell's Simone Daniels. The movie didn't blow critics out of the water, nor was it a smash hit at the box office, but starring in a teen Disney movie appears to be a good launchpad for a career in Hollywood.

Shameless (2011 - present)

If there's anything besides Gotham people will recognize Cameron Monaghan from, it's Shameless. He's carried a principal role in the American remake of the British series since 2011, playing Ian Gallagher. In a way, the series has allowed Monaghan to grow up—as an actor and in real life—and take his career to the next level. Since he turned 18, the comedy-drama has (legally) explored the character's sexuality, which is important considering that Ian is homosexual. In fact, critics have not only praised Monaghan for giving one of the best performances of a gay character on television, but also for helping anchor one of the most emotional and convincing same-sex relationships.

Vampire Academy (2014)

In between seasons of Shameless, Monaghan appeared in Mark Waters' Vampire Academy, based on the 2007 novel of the same name by Richelle Mead. Monaghan played Mason Ashford, a dhampir (vampire-human hybrid) and one of Rose Hathaway's (Zoey Dutch) best friends. Aside from the fact that Mason is romantically interested in Rose, he tends to help her out quite a bit throughout the movie (and the novels). Unfortunately, the movie bombed at the box office, and critics didn't like it any more than audiences, which meant the studio's plans to complete the Vampire Academy franchise (with movies based on the remaining novels) were aborted. Still, the flick was one of the first major productions Monaghan took part in as an adult, and it gave him a chance to get his name out there with moviegoers, especially fans of the Vampire Academy novels.

The Giver (2014)

The same year Vampire Academy was released in theaters, Cameron Monaghan appeared in another Hollywood adaptation of a famed young adult novel: The Giver. The Philip Noyce-directed movie is based on the book of the same name by Lois Lowry, which depicts a world in which the citizens conform to society's fundamental needs. Everything is colorless and emotionless, and everyone is content—except for the Giver, who is tasked with remembering the way the world once was. Jeff Bridges plays the Giver in the adaptation, with Brenton Thwaites playing Jonas, the Receiver. Monaghan portrays Jonas' best friend, Asher, alongside Odeya Rush, who plays Jonas' friend and romantic interest, Fiona. As with Vampire Academy, The Giver wasn't received warmly by critics, who argued the movie didn't do the source material justice. And while it didn't flop at the box office, the film wasn't a breakout hit either.

Mercy Street (2016)

Having a main role on Shameless for the past several years hasn't barred Cameron Monaghan from headlining other shows: in 2016, he took a role in the PBS period drama Mercy Street. Created by David Zabel and Lisa Q. Wolfinger, the series takes place during the American Civil War, and follows doctors and nurses who treat both Union and Confederate soldiers with equal care at the Mansion House Hospital. Monaghan had a central role in the series' first season, which aired on-demand in 2016, playing Tom Fairfax, a patient at the hospital and Alice Green's (AnnaSophia Robb) "beau." In the show's fourth episode, Tom commits suicide after suffering from what appears to be post-traumatic stress disorder. His body was found in the next episode, marking the unfortunate end of Monaghan's stint as a Confederate soldier.