Booyakasha! Nickelodeon's Teenage Mutant Ninja Turtles hit the stage at San Diego Comic-Con on Saturday, bringing a panel packed with talent: voice stars Sean Astin (Raphael), Rob Paulsen (Donatello), Greg Cipes (Michelangelo), Seth Green (Leonardo), Josh Peck (Casey Jones) and Kelly Hu (Karai), as well as executive producers Ciro Nieli and Brandon Auman.

Of course, Green is new to the fold and will begin voicing Leo at the start of Season 3. "I am a lifelong fan of the Turtles," he said, "so getting to be a part of this is incredible." He also noted that his wife, Clare Grant, already "had the hots for Leonardo," so when the offer to play Leo on the show came along, Green immediately said "Yes!"

Meanwhile, coming off the exciting cliffhanger in "Vengeance is Mine" -- in which Karai was transformed into a serpent mutant -- Hu quipped, "I hate when that happens," referring to her previous mutant role as Lady Deathstrike in X2. Added Auman, "We thought about mutating her into Venus de Milo, because you guys love Venus de Milo, right? No? I guess not!"Nieli also teased an upcoming episode, airing soon (before the finale). "It's really big, it's really dramatic," he said, "but the one new place that we're going to see and go to is Dimension X."

A still from the upcoming Season 2 finale.

This followed with a clip (), in which Leo, Raph and Donnie enter the Kraang home world in search of Mikey, who inexplicably got sucked into Dimension X. Here we saw giant worms, a massive eyeball shooting lightning, large floating land masses made of crystals, and a deep void of purple space. Along the way, the guys run into several other monsters, including a huge bug/rock creature. With the Turtles unable to defeat it, a stranded Mikey swoops in and shoes the "Rocktopus" away. Then, elsewhere, we see none other than Leatherhead being tortured by Kraang Soldiers!As for the rest of Season 2, Auman mentioned that the finale this year is going to be even more epic than Season 1's -- "Michael Bay epic!" he joked. The panel then screened a new trailer for the Season 2 finale (video coming soon!), which featured the Turtle Mecha hinted at in "Plan 10," another duel between Shredder and Splinter, a face-off between Shredder and Leatherhead, plus another Kraang invasion -- only this time on a much larger scale. As Casey put it at the end of the trailer, "Dude, this is worse than that giant Technodrome thing last year!"Closing out the panel, Nieli revealed some all-new characters for Season 3, including the Creep, a bog monster-looking creature that attacks April and Casey in the woods; the Dream Beavers, oversized beaver monsters, voiced by Robert Englund (Freddy Krueger himself!) and John Kassir (the voice of the Crypt Keeper); and Napoleon Dyna-frog, a lackadaisical mutant frog voiced by Napoleon Dynamite's Jon Heder.Nieli also presented a couple of classic character reboots. The first was Mondo Gecko, who in Nick's TMNT will be voiced by the original live-action Michelangelo, Robbie Rist. The second and final character revealed for Season 3 was the one and only Muckman. And, as a special bonus, Cieli unveiled a brand new vehicle that fans might recognize: the Party Van!

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