Flying Dutchman's ship

First, the developers stated the game will launch with 20 characters (so far 17 have been confirmed through trailers), and two more and DLC is on the way after that! Aang and Korra haven't been officially revealed yet. The character select screen and stage select screen seem to have been leaked too which possibly confirms Aang, Korra, and Toph as a third Avatar character. The two characters releasing after the game comes out were shown, but they were censored out. Only thing you can really see is what appears to be shoes on one of them. Someone thinks this is Jimmy Neutron. They also say voice acting and more may be added down the road which is really exciting to think about. As a Smash and Nickelodeon fan, I am definitely getting this game!