When Nickelodeon's "Teenage Mutant Ninja Turtles" animated series held a panel highlighting events from the upcoming third season, the show also used its Comic-Con International in San Diego pulpit to preview a few new characters and stories set to debut in the fourth. Panel moderator Andre Meadows of YouTube channel Black Nerd Comedy appeared in a pre-taped video pretending to do a "Ninja Turtles" recap. After a few jokes, Meadows "realized" he was at Comic-Con and ran off camera, instantly jumping into "live action" on the panel room stage.

Meadows quickly introduced the executive producers of the show -- Ciro Nieli and Brandon Auman and the actors who voice the titular turtles: Seth Green (Leonardo), Rob Paulsen (Donatello), Greg Cipes (Michelangelo), and Sean Astin (Raphael). The producers and turtles were joined by the show's villainous voice actors as well: Kevin Michael Richardson (Shredder), Eric Bauza (Tiger Claw), and Fred Tatasciore (Rocksteady).

Meadows recapped the third season, noting that a theme of maturity ran through the episodes, particularly when the turtles suffered a major defeat and took refuge at a farm. "I was always a fan of that story arc in the original Mirage [comic book] series," said Nieli. "Leo was going through a lot of physical problems and fears and doubts. That farm house was a good place for them to heal their wounds and get their mojo back. It was also nice because I always wanted to see the turtles back in nature. What would it look like if the turtles were meditating on a rock?"

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Meadows pointed out that he noticed references to horror elements pop up while the turtles stayed at the farm house. "Ciro and I are huge horror fans," said Auman. "I think you're going to see more horror references as we go, but we grew up watching all these amazing horror films, so we tried to incorporate as much as we could into season three."

Meadows noted that the show had also introduced the Mighty Mutanimals into the third season and asked if it was challenging to re-introduce classic characters in a new way.

"That's the goal," said Auman. "We want to bring back these classic characters from the comics, the O.G. 80s and 90s Turtle cartoons... We want to bring them back and we want to put our own spin on them. We want to do something cool and unique." The crowd liked this admission, judging by the applause.

Meadows then moved his attention to the cast members. "A couple of weeks ago I got to see them do a voice recording session," said the moderator. "These guys work hard. They do multiple takes, they bring emotions to their lines, they do a really great job." Meadows then asked Seth Green about the grunts and fighting noises the actors have to do during battle scenes. "Those are you guys doing those. What's it like bringing emotion to random noises like that?"

"I always assumed after recording literally thousands of 'OOH,' 'AHH,' 'HIYA' kind of things that they'd build up a sound bank that they'd draw from," said Green, "but we actually do new sounds every scene!"

Greg Cipes then joked that "Seth insists on punching me in the stomach."

"It's all about realism," said Green. The pair of voice actors then jumped up and began to throw mock punches with exaggerated noise. "Years of training. years of training," Green joked

Once the fake dust from the fake fight settled, Sean Astin added, "And then there's looping where they've finished all the animation but you're going back because your sounds don't exactly match what [the animators] did and you've gotta go 'I think his mouth is going AAARGG! but I'm not quite sure."

Green laughed "Yeah. He's got gritted teeth so maybe it's more of a YEEEAARRGH!"

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Meadows asked Green about his experience joining the cast as Leonardo in season three. "It's been amazing. I love the turtles as a property, so getting to be a part of it, especially in this role is insane for me," said Green. "I've also known all these guys for a long time so we have an incredible repoire."

"One of the things I noticed is that when Leonardo's injured, Raphael steps up," said Meadows. "Is that a fun balance to play with that character, Sean?"

"Yeah, I think it's fun for Brandon and Ciro to take a character who's known for being this badass tough guy and playing against that," said Astin. "And I think he gains a little more respect for what Leo's role as a leader is."

Meadows then shifted focus to Rob Paulsen by asking about Donatello's on screen romances with Bigfoot and April O'Neill. "Bigfoot is a fine dancer and a genuinely decent being," joked Paulsen. "But really just stinks. Just so smelly. And April doesn't. She smells great. I am grateful to play any character any time, in which I get anybody to give me a smooch." With this, Astin leaned over and kissed Paulsen on the cheek. "Awww, thank you," said Paulsen.

"Greg, what's fun about Mike is that he's the jokester, but when they go to Dimension X, he's the leader," stated Meadows. "What is it like playing that part?"

"It's like people are finally seeing me for who I really am," said Cipes. "It feels good!"

Turning attention to Tatasciore, Meadoes asked the voice actor what it felt like to see his character transform into Rocksteady -- a character that caused the audience to erupt in cheers just with the mention of his name.

"We are appreciating this." replied Tatasciore in a thick Russian accent. "I didn't realize that it was going to go this way. I didn't see him turning into the mutant. Playing off of J.B. Smoove is just... wow! It's a blast. I think we are finding out that he's actually deep down inside kind of a softie."

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Standing in contrast to classic characters like Bebop and Rocksteady is Tiger Claw, the villain voiced by Eric Bauza. "I get to join this universe with an original spin," said Bauza. "My dream is that 20 years from now another Filipino Canadian might have another shot at this voiceover thing. It's been a thrill and I'm so thankful to the fans."

Meadows then asked Richardson about portraying the iconic villain Shredder. "The guy is just bent on vengeance," replied Richardson. "He's living a lie. He's a little messed up. He's a deep cat and he's just into power. And what do people with power want? More power."

"What better power than that powerful voice?" asked Meadows.

"Yes," boomed Richardson into the microphone.

"I do all his ADR when he's not there," joked Cipes. Cipes and Richardson then began bickering in each other's voices.

The group then welcomed voice director Andrea Romano to the stage and performed a table read of a script written for Comic-Con. In the story, the Ninja Turtles investigate Comic-Con in their trench coat disguises and run into Shredder and his minions on the floor. The script was filled with Comic-Con references and nods to the fans -- such as the moment that "Lord of the Rings" actor Sean Astin exclaimed, "Turtles dressed as elves, dwarves, and hobbits make zero sense! Seriously, turtle hobbits!?"

After the read, Neili introduced a clip from a future third season episode that featured Zog the Triceraton in a fight with Raphael. Raphael ends up befriending the alien, who is searching for the Krang. After the clip, Nieli and Auman showed slides of Zog's character design, which was finalized by Phillipe Smith, and announced that Lance Henriksen is voicing the character. "We're big Lance Henriksen fans," said Nieli.

As the show continues to explore the original TMNT universe created by Kevin Eastman and Peter Laird, the turtles will travel to space in season four. Nieli and Auman revealed the design for the turtles' space suits. "The trick was, 'How do you keep your turtles looking like turtles and make them able to live in space?'" said Auman.

Character designs were revealed for Lord Dregg (Peter Stormare), Mozar the Triceraton (Michael Dorn), and Armaggon (Ron Perlman). "We like the idea of being in space and 'you're gonna need a bigger boat,' so I thought of a shark inside a mechanical shark voiced by Ron Perlman," said Nieli.

Upcoming characters also include Mona Lisa, who will be voiced by Zelda Williams. The creators were very excited about introducing the character, who will be Raphael's romantic interest.

"Is that it?" asked Meadows. "Or do you have one more?"

"We're really big science fiction fans," said Auman. "We're huge fans of British science fiction. Like a certain space doctor we're really big fans of..."

"Doctor who?" asked Meadows. "Doctor what?"

A short clip came on the monitors that revealed the Fugitoid -- a classic Mirage Studios character -- will make an appearance in season four with former "Doctor Who" David Tennant voicing the android.

"Teenage Mutant Ninja Turtles" will return to Nickelodeon on August 2 with an episode titled "Turtles in Time."