Introduced in a Season 1 episode of Gotham, Jonathan Crane was a timid teen who aided his deranged father Gerald in murdering people by exploiting their worst fears. Using the glands of his victims, Gerald developed an anti-fear serum that he injected into his son, leaving the boy traumatized by hallucinations of scarecrows and confined to Arkham Asylum. But with the fourth season of the Fox drama, Jonathan is back and on the loose as the sinister Scarecrow.

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In Gotham's season premiere, Jonathan (played once again by Charlie Gahan), was released into the custody of the criminal Merton's Gang, who wanted his father's formula for use in their plans. However, Jonathan’s mind snapped when they locked him in a room with an actual scarecrow. Dismantling the tattered strawman and donning its clothes, he closed out the episode by proclaiming that Jonathan no longer exists, thus beginning his reign of terror as the Scarecrow.

Ahead of tonight’s episode, "A Dark Knight: The Fear Reaper," Tahan spoke with CBR about finding the Scarecrow’s voice, the creepy costume, and whether Jonathan Crane is afraid of anything.

CBR: Jonathan Crane hasn’t appeared on Gotham since Season 1, so how shocked were you to get the call to reprise your role?

Charlie Tahan: I was happy. I’m not totally caught up with the show. I watched the first season, but it’s been great. I always wanted to come back. I only played Jonathan in the first season and it was kind of Scarecrow’s origin story. We needed to come back and finish that arc.

There have been multiple iterations of the Scarecrow in comics, cartoons and movies. What were some of the cornerstones of the character you wanted to incorporate?

I’m a fan of superhero stuff, but I never got into Batman comic books that much. I’m not sure about all the versions of Scarecrow in the canon. I love Christopher Nolan’s movies; Cillian Murphy’s Scarecrow was great. I have a friend who I went to high school with, and who is super into comic books. He has a thing for Scarecrow. He inhales all that stuff, so I asked him for pictures, references from comic books or audio recordings from the Arkham games. He helped out a lot. I actually tried to do an exaggerated version of my friend’s voice for this part. They put a voice distorter on in the end, but I tried to copy my friend’s cadence.

After Jonathan was injected with drugs, and his stint in Arkham Asylum, how mentally unstable is he?

Well, I think the Scarecrow is a totally different person. When I shot this for the first season, it was obviously open-ended. But, I didn’t know if I was coming back at all. I was pretty catatonic at the end of Season 1. He’s just locked away his thoughts for a few years.

Grady Harris and his gang of thugs unintentionally unleashed this monster. To begin with, what was it like putting on the Scarecrow costume, and how did it inform your performance?

It was very hot and very itchy. I didn’t think about how to walk or anything before. I put on the costume. They put these boots on me with little heels, to prop it up, and to make me walk a little weirder. They had these gloves. They put these felt tops on the gloves. I had these pointy fingers. I had this scythe. I think they did an amazing job on the costume. It’s beautiful.

At this point, Scarecrow is on the loose. What does he want?

I don’t know how much I can give away. He’s sort of trying to build an army with this toxin. Scarecrow might start brainwashing people. I’m not exactly sure what his endgame is -- I don’t even know if he knows. He has this revelation that he doesn’t have to fear fear.

What else can you tease about Scarecrow’s arc?

You can say the Scarecrow was forged in Arkham Asylum. Maybe he might be a little angry with the orderlies and staff at Arkham.

Lastly, what scares the Scarecrow?

Scarecrow and his father scare him. The thing is, when he becomes the Scarecrow, he gives up on trying to fight it. I don’t think he’s left with much fear at all.

Airing Thursdays at 8 p.m. ET/PT on Fox, Gotham stars Ben McKenzie as James Gordon, Donal Logue as Harvey Bullock, David Mazouz as Bruce Wayne, Robin Lord Taylor as Penguin, Cameron Bicondova as Selina Kyle, Erin Richards as Barbara Kean and Sean Pertwee as Alfred Pennyworth.