WhileThe Penguins finale was filled with twists and turns as the series cemented its place in comic book TV royalty, perhaps its unsurprising to learn that star Colin Farrell had a terrible time making it. No prosthetic wang needed this time to make things miserable, but instead the sheer horror of having to work through one of the series darkest moments. That is, of course, when Oz makes the cold calculation that in order to stop his rivals from using anyone close to him to get to him, he must brutally throttle poor young Vic to death with his bare hands. Its a moment among many across the show that has transformed The Batmans take on Oz from the almost charmingly affable, but sleazy mobster he was in the film to an absolute terrora transformation that Farrell apparently wanted to resist to his very core up until the last moment.Every fiber of me, of Colin, resisted it because theres a part of you that, no matter how dark a character youre playing and no matter how you accept swimming in those waters of the impossibility of any comeback into the affections of the audience, theres a part of you that always wants the audience to be open to the idea that you can redeem yourself, Farrell recently told Collider of the shock he felt reacting to Vics death in the finale. No matter how dark your character is, you always want them to feel that maybe there is some sliver of humanity left, that if the right thing was done in a well written scene in the right moment, you could redeem yourself. Im not sure thats possible anymore by the end of episode eight. So, knowing that I was going into that kind of degree of psychological finality and embodying the character with a kind of a depth of cruelty that is articulated in that scene, it was tough, man. Farrell knew from the get-go that part of whatThe Penguin was going to do was completely kill off any idea that Oz would remain the man he was inThe Batman, ahead of his return in the long-in-the making The Batman Part II. But after working with Rhenzy Feliz for the best part of a year and coming to the final days of production, the actor wasnot having a pleasant time separating fiction from reality.There was very little conversation on the set that night. We knew where we were. There was a slab that we were sitting on by the water, Farrell continued. We knew our lines as actors are supposed to, and we just went, and we did the takes, and we did as many angles as we had to do, and I fucking hated it. I hated that scene. I really did. I was fucking so pissed off. It felt in performing it asguess what?you would like it to feel in viewing it. It felt gross, it felt cruel, it felt absolutely insane, and it felt like Oz was reaching a point of no return. You bring it home at night, and that was a sticky scene. I had to have a shower with a wire brush at the end of that night, he concluded.As horrified as Farrell is, hopefully the overwhelmingly positive response to the finale will make him feel like he needs to scrub a little less deeply when he hits the showers this week. The Penguin is now streaming in its entirety on Max. Want more io9 news? Check out when to expect the latest Marvel, Star Wars, and Star Trek releases, whats next for the DC Universe on film and TV, and everything you need to know about the future of Doctor Who.