Turtle Power, indeed! Today at Wondercon, Nickelodeon's TMNT paid a visit to the LA Convention Center to preview what's in store for the rest of Season 4. Joining the panel were executive producer Bradon Auman, as well as voice cast members Rob Paulsen ("Donatello"), Greg Cipes ("Michelangelo"), Kevin Michael Richardson ("Shredder"), Christian Lanz ("Fishface") and special guest Zelda Williams ("Mona Lisa") making her WonderCon debut.

Obviously Mona Lisa has been one of the more notable additions this season. "You kind of walk in as the new kid in school," the actress said of joining the show, "but it's been very fun." Having voiced both Mona and Kuvira on The Legend of Korra, Williams now has a track record of playing badass females on Nickelodeon. "I have a feeling that's all I'm going to get to play: dictators and six-foot-tall lizards," she joked.

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Tokka's new look on Nick's TMNT

Alas, Shredder hasn't appeared much in Season 4, but Richards mentioned how he was still reeling over his character killing Master Splinter at the end of Season 3. "Personally, I wasn't happy about it, but Shredder was ecstatic," the actor laughed. "I put a lot of energy into that moment... but I think you guys are in for a big surprise [in the near-future]. It's out-there as far as Shredder goes." (Hmm, Super Shredder anyone?)Looking ahead, our heroes are still traveling through space to track down and destroy the last piece of the black hole generator. After his defeat a few week's back, Lord Dregg will return in a future episode, in which the Turtles discover the alien villain's lair on the planet Sectoid 1. A clip from the installment showed the Turtles, accompanied by Mona Lisa, falling down a Sarlacc-like pit and into a monstrous belly.In episode 13, called "Ever Burning Fire," fans will meet two new characters. The first is Chompy Picasso (which you can see here ), a cute little alien turtle that becomes Raphael's new pet, replacing the former Spike.The second will be familiar to fans of the live-action Teenage Mutant Ninja Turtles II: Secret of the Ooze -- Tokka! Only, "This version of Tokka is a little bit different," Auman said; he's a giant, magma rock kaiju monster that breaths fire. In the main storyline, Tokka safeguards the third and final fragment of the black hole generator. Check out his new design below (via TMNTMaster ):Of course, this weekend marks the debut of TMNT's big crossover episode "Trans-Dimensional Turtles," as the Green Team joins forces with their 1987 counterparts to stop Krang (that's "Krang" with one "a"!) from destroying both the 2D and 3D worlds. As a special surprise, the panel screened the entire episode, which debuts tomorrow. Following the screening, Auman also teased the '80s Turtles may even turn up again in a future episode!Keep an eye out for IGN's full review of "Trans-Dimensional Turtles" after it airs Sunday on Nickelodeon.

Max Nicholson is a writer for IGN, and he desperately seeks your approval. Show him some love by following @Max_Nicholson on Twitter and MaxNicholson on IGN.