Well here it is now, the Dodo Dragon is a Earth and Air elements dragon. Breeding takes 16 hours!
Earth Dragon + Chrome Dragon = Dodo Dragon
Earth Dragon + Snow Dragon = Dodo Dragon
If you have any other working breeding combos feel free to leave any tips!
If you want to add me in the game my gamecenter name is prplrush. Feel free to follow my blog for more updates, via google friend connect. (right below this post) and google + this post