The panel aired this teaser for the TMNT Season 1 finale

If there's one thing fans can accuse Nickelodeon's "Teenage Mutant Ninja Turtles" cast and crew of, it's having a party even when there's no pizza. The energetic and lively panel hosted by Executive Producer Peter Hastings played to a packed house at Comic-Con International in San Diego and included EP Ciro Nieli, Story Editor Brandon Auman and the voices of Raphael (Sean Astin), Donatello (Rob Paulsen, who voiced Raphael in the 1980s "Turtles" cartoon), Michelangelo (Greg Cipes), April O'Neil (Mae Whitman) and The Shredder (Kevin Michael Richardson).

"'Ninja Turtles' has only been on the air for ten months now, and it's already become a global phenomenon -- so thank you!" Hastings declared. With Season One wrapping in August, the "Ninja Turtles" team has big plans for Season Two, and the panel had fans mesmerized with teaser footage and character reveals throughout.

"We're launching into Season Two with new characters and places to go," Hastings continued. "Everybody was like, 'This show's gonna suck! I hate it! They're messing with my childhood!' But the response has been so great."

Commenting on Roseanne Barr voicing Prime Kraang, Hastings said, "We just thought who's the scariest person we can get?"

"People often ask what drew me to the part of Raphael. Nothing did. It's Raph!" Astin said. "When Cipes is voicing Michelangelo, we're laughing so hard it costs the studio money."

"I'm just so excited voicing Mikey," Cipes said in his normal speaking voice -- which sounds exactly like his Turtle character. "Growing up as a kid watching the 80s cartoon, he's made me who I am today. He got me into martial arts, skateboarding, meditating, eating pizza."

Fans are looking forward to the debut of Casey Jones

"It's indescribable what it's like to get another ride in the Turtle Van twenty years later," Paulsen said. "This is a great example of why this iteration of the show is so great -- we have an enormous fan base from these cute kids in the first row to guys like us who just got on the AARP mailing list. It's unbelievable."

"We're all a Turtle at heart," Cipes declared.

Hastings asked Whitman, the voice of April O'Neil, what animal she'd choose to be given the choice. "If I don't say a turtle I'm gonna get mobbed... but maybe a wolf?" she answered. "It's amazing for me -- these guys are like my family. I love Nick and everybody and these guys are literally like my brothers. It's cool to be the girl in the room -- I get to represent all the badass ladies out there."

"I originally read for April. They didn't like it," Cipes joked.

"We love April and give her a lot of stuff to do in the show and it's going to continue," Hastings said. He then had Richardson read an impromptu advertisement for hotel linens in the voice of The Shredder which had the audience -- and panelists -- cracking up.

"What better way to up the ante for Season 2 than having a lot of mutagen get lost!" Nieli said, revealing the overlying theme of Season 2. A brief clip showed cans of mutagen falling from a Kraang ship into New York City, with the voiceover saying, "New York City gets a few more mutants."

"We wanted to kick off a whole spree of new mutants," Nieli said, showing an image of newcomer, Newtralizer. "Newtralizer is a character I came up with as a kid. He's an intergalactic bounty hunter."

A brief video showed Newtralizer -- voiced by Danny Trejo -- blowing away a couple of Kraangs, then eating a third and taking possession of some enhanced armor.

"I want the Newtralizer toy!" Cipes shouted.

Corey Feldman returns to TMNT as the voice of Slash

Nieli then announced the introduction of Slash, voiced by Corey Feldman, better known to TMNT fans as Donatello in the 1990 "Teenage Mutant Ninja Turtles" movie, and again in 1993's "Teenage Mutant Ninja Turtles III." "He's like the fifth Turtle," Nieli said of Slash.

"His design came mostly from the classic toy," Nieli said when Mutagen Man appeared on the screen. "We all have one on our desks and it was only a matter of time before we slipped him into the show. He's actually Timmy, the kid who used to be The Pulverizer -- we take our time telling his story. He's vital in the formation of Casey Jones as a vigilante."

Speaking of Casey Jones, Nieli rolled some clips from the character's first appearance in the show. He rescues April from Mutagen Man, plays some hockey and even sports a goalie blocker with the name "Laird" written up the side.

"We have April at a young age so we set Casey a little older," Nieli explained. "He's the same Casey we know, only we start with him a little earlier in the storyline. His grades aren't going well and he needs April to help him. He also sometimes paints his face because he's terrifying and weird. Josh Peck voices him, who was born in Hell's Kitchen but lives in New York -- he's totally into hockey, too."

Three more original characters introduced in Season 2 include Squirrelanoid, Sir Malachi and Tiger Claw. "Squirrelanoid is one of the first animals that gets a lick from the falling mutagen," Nieli said. "A lot of us love to roleplay so we brought in Sir Malachi the wizard." When Tiger Claw's image appeared, it evoked a series of "Ooos" from the crowd. "Shredder is ticked at his lack of manpower, so he goes to Asia and brings back Tiger Claw who's a master of all weapons," Nieli continued. "His tail was chopped off by a person he's still searching for to this day."

Fans went nuts at an image debuting Baxter Stockman as a mutant fly. "Poor Baxter," Nieli said. "Poor Phil LaMarr (the voice of Baxter). This is going to be the greatest action figure ever. "

A video sequence was then played with the title card "TMNT Changes," and began with a scene featuring Michelangelo in a moth costume. There will be a Turkey Turtle episode where "at some point Raph's head gets transformed into a turkey head." Then, Mikey's supposed to watch April's cat but it gets hit with mutagen and the mutant Ice Cream Kitty is born, "which is literally a kitty made of ice-cream. We thought, what if mutagen drops near ice-cream and a cat licks it?"

"It's the best kind of pet," Cipes said. "If you get hungry you can just lick it."

"If you know these characters and are familiar with this stuff, we're rolling things out slowly," Hastings said. "We're spreading it out. So don't freak if you don't see your favorites in the first four episodes or so. We're creating new backstories for them, but with our eye on the original lore."

Auman brought up a new Activision videogame based on the show, due out this holiday season for XBox 360, PS3 and Nintendo Wii. It's a more kid-friendly version of the Turtles, unlike Activision's other TMNT game, "Out of the Shadows" which is darker in tone. Auman, who worked on the game, said, "It's way better than the 80s old school NES game with the original voice actors of the show. It's a side scrolling brawler."

A demo clip was shown, strongly reflecting Nick's version of the Turtles in a beat'em up style brawler where you choose your Turtle and take down hordes of enemies, including Foot Soldiers, Kraangs and Mousers.

"It's awesome doing the voices for the game," Astin said. "'Go back!' 'Go forward!' 'Go left!' 'Go right!'"

"When you leave the game on pause, our characters are like 'Are you still there?' 'Are you still there!?' I can see parents being like 'Shut up!'" Whitman said.

At this moment Hastings introduced the show's voice director, Andrea Romano, who was seated in the crowd.

"Next to my wife, I've never had so much fun being told what to do by a woman," Astin joked.

Next, Hastings introduced TMNT co-creator Kevin Eastman who was also amongst the crowd. He stood to a thunderous ovation.

"Eastman puts his spirit into this show by his suggestions -- it motivates us to do new kinds of characters. It's awesome when he comes by the office to sign shit for us," Hastings said.

"That man put my kid through college!" Paulsen declared.

"That's my father right here! He's full of so much love," Cipes said, bursting into a beatbox rap about how awesome Eastman is.

"This entire time I've had goosebumps listening to and watching what these guys have done," Eastman said, briefly taking the podium. "I could not be prouder -- I'm so excited and this is the best version of the Turtles ever done."

With the crowd in a frenzy, Hastings opened the floor to questions.

Nieli answered that the "Enter Shredder" episode is the most positively received by fans. "It's a classic -- the TMNT fight Shredder," he said. As for the most polarizing, "The 'Cockroach Terminator' episode, which I totally love."

A fan asked what's going on with Leatherhead. "Leatherhead will be back in Season 2," Auman said. "I can't tell you how or why but he will be back."

Someone from the crowd shouted, "Bring back Bebop and Rocksteady!"

"Patience," Nieli replied. "We like them too. Patience."

More fans wanted to know if other TMNT co-stars and characters will appear in the show, like Stan Sakai's Usagi Yojimbo, the female turtle Venus from 1997's live action "Ninja Turtles: The Next Mutation" show or even Vernon from the 80s cartoon. "We'll see a few of them," Auman answered. "From the 80s cartoon, we'll for sure see April's friend from Channel 6, Irma. We want to keep the rest a secret. You'll have to watch -- you'll be excited!"

A fan asked what's up with April's powers and referenced the clip shown earlier. "There's something tricky going on," Whitman said. "I can't talk about it, but it's going to get so cool and weird. Her ninja skills are improving -- she spends every minute with Splinter."

"I know a hot chick when I see one," Paulsen said when asked if April will ever realize Donatello likes her. "I'm all over her unless Casey Jones shows up!"

To close, Hastings did a survey of which Michelangelo catchphrase the audience preferred -- the classic "Cowabunga" or the new "Booyakasha." After having the crowd shout their preference, he said, "Yeah, there's a definite age difference there," noting how "Cowabunga" was all deep, older voices and "Booyakasha" was all higher toned, kid voices.

While the panelists were getting up to leave, Richardson grabbed his mic to give the final word. "Thank all of you for loving this big black ass of a Shredder!"

"Teenage Mutant Ninja Turtles" airs Saturday mornings at 11am EST on Nickelodeon