Premiering this Saturday, December 15 is an episode entitled “The Metal Face of Comedy,” in which through an unusual accident Joker’s personality is downloaded into a nanite entity, and the digitized Joker is even more threatening than the original. Kevin Michael Richardson provides a double dose of his usual sense of devious joviality as Joker. Vinton Heuck directs the script from writer Alexx Van Dyne.

The “Metal Face of Comedy” airs Saturday, December 15 at 11:30 a.m. ET/PT as part of the No. 1 rated Kids’ WB! Saturday morning network lineup on The CW.

Premiering this Saturday, December 15 is an episode entitled “The Metal Face of Comedy,” in which through an unusual accident Joker’s personality is downloaded into a nanite entity, and the digitized Joker is even more threatening than the original. Kevin Michael Richardson provides a double dose of his usual sense of devious joviality as Joker. Vinton Heuck directs the script from writer Alexx Van Dyne.

The “Metal Face of Comedy” airs Saturday, December 15 at 11:30 a.m. ET/PT as part of the No. 1 rated Kids WB! Saturday morning network lineup on The CW.

Mulroney has starred in nearly 60 films and television series, including My Best Friend’s Wedding, About Schmidt, The Family Stone and Must Love Dogs. He said he enjoyed the voiceover experience and hopes to work in the medium more often. He also voiced a character in Bill Plympton’s 2007 animated film Hair High. He particularly enjoyed the specific direction and recording with an ensemble cast on The Batman.

“It’s a really comfortable environment, especially recording with the entire cast and working with the pros, that was the most fun,” Mulroney said. “It all came pretty natural, but then again, you’re really helped through it.

“It’s not like on a film set where you don’t really want the director to give you a line reading,” he adds. “Here, I rely on it. It’s a different medium.”

Unique to Mulroney’s previous acting experience was his ADR (additional dialogue recording) session, where he recorded, to picture, more lines and fixed some old dialogue, as well as adding all the physical sounds that go with the fight sequences. Renowned voice director Andrea Romano guided Mulroney through both of his “Ring Toss” sessions.

“Doing all the grunts and groans has its charm, too,” Mulroney said. “There are experts here in the studio who know exactly which type of groan goes with which picture, so I pretty much just do what they say.

Mulroney said acting on the show would be difficult without expert guidance.

“(Andrea) knows exactly what the sound is that you make when there’s an impact and what’s the sound of you throwing a punch, when you’re getting blown up or when a ceiling falls on you,” he says. “That may sound funny to say, but it sounds good in the recording.”

The interplay between Green Lantern and Batman was another enticement in luring Mulroney to the project.

“I really liked the dynamic between Green Lantern and Batman, that was my favorite part of the storyline,” he said. “With the Justice League, we’re talking about a whole league of super heroes, so how is everybody supposed to get along? They’re fighting for the same cause, but there are some personality conflicts. That was a fun part to play.”

Mulroney’s distinctive voice is a natural for animation. To him, though, the experience was somewhat surreal, particularly in comparison with his usual on-camera roles.

“I’ve always had this voice,” Mulroney said. “Most of my brothers had their voice change, but I was absolutely Froggy, you know, Froggy from Our Gang. I’ve sounded like this since I was 5. I’m used to it, so it’s fine.”

“In live-action, It’s funny to see yourself on the screen; but to only hear your voice coming out of a cartoon character is still like it’s somebody else’s voice sometimes.”

Mulroney adds that working on The Batman was a bit of a surreal experience, especially when it came to hearing his voice.

“I was fine working on (The Batman) originally, just recording the script into a microphone,” he says. “But to come in to fill in the gaps and to watch the TV screen and hear my voice recording coming out of the character, and not coming out of my mouth, is a bit of a peculiar experience.”

As reported in TV Guide last week, Dermot’s brother and sister-in-law are Kieran and Michelle Mulroney, the screenwriters on Justice League of America, the upcoming Warner Bros. live-action film. Mulroney sees symmetry to their current projects.

“Kieran and I grew up reading DC comics,” Mulroney said. “We had a whole system where, once a week, we’d take a trip to the little store that sold the comics. I have a couple of brothers, and we’d all fight over who got which issue. So there’s a long history of comics in the family.”

Mulroney is going to keep the super hero theme running through the family. He plans on watching the episode with his 8-year-old son.

“He’s going to love it,” he said.

Green Lantern is just the latest DC character to swing by The Batman. Superman, Green Arrow, and The Flash have already stopped by, and Hawkman and the entire Justice League are still slated to make an appearance before the end of the season.

More images from The Batman episode “Ring Toss” can be seen here and here.