Playing a disturbed teenager seems to come easily to heartthrob Ezra Miller. The New Jersey, United States native made waves with his portrayal as the mass-murdering schoolboy in the critically acclaimed 2011 movie We Need To Talk About Kevin.

He then played a deranged prisoner in The Stanford Prison Experiment, a movie based on the real-life California’s Stanford University Psychology Department studies conducted in 1971.

In his latest endeavor as Credence Barebone in Fantastic Beasts And Where To Find Them, Miller, you guessed it, plays a mentally unstable boy.

So what is Miller’s fascination with such difficult characters?

“When I was a kid, I used to say ‘the challengier (sic), the better’, and I stand by that ethos. It’s part of the intrigue of being an actor – to explore a wide range of possibilities that exists within a human being,” he shared during a recent roundtable interview to promote Fantastic Beasts in New York.

There’s another noticeable trait in Miller’s movie roles, actually. In every film, the 24-year-old actor never fails to rock a distinguishable hairdo, with the most “unfortunate” reserved for his new movie.

“I have more hair than I ever know what to do with… so for a hairstylist, it’s like a lot of raw material to work with, and they get excited and try new things. The Fantastic Beasts hair and makeup department head Faye Hammond and I looked at images from 1920s, and saw this boy with a haircut like that. It was a bowl cut, but not even the whole bowl, it was like a saucer cut. And we pictured it being done with dull scissors – a painful monthly process for Credence,” shared the currently floppy-haired actor.

His chauffeur had laughed at him for the first few weeks, and the actor even resorted to hiding his awful haircut under hats.

“But I adapted and took on the ability to fly the freak flag, so the hats went away.”

(Read also: Review: Welcome to magical universe of 'Fantastic Beasts')

This image released by Warner Bros. Entertainment shows Ezra Miller in a scene from, "Fantastic Beasts and Where to Find Them."(Warner Bros. via AP/Jaap Buitendijk)

Miller discovered acting as a child, which he says, makes everything in retrospect a little confusing as it’s hard for him to delineate simple play-acting as a kid, or when he was actually acting.

“I remember when my sister explained to me that the genie that came out from the lamp in Aladdin was not a real person. I was crushed because that was my initial interest in acting. I wanted to be a blue genie,” he said with a twinkle in his eyes.

Well, he may not be playing a blue genie, but snagging the role as The Flash in the DC Extended Universe is equally a sweet deal. Miller revealed that he had just wrapped up filming Justice League, and is currently focusing on his music career.