"Oh hey there Oogi, can't wait to see more of you in Book 3!"The caption specifically draws attention to Oogi, the flying bison. Perhaps it is meant to hint that we will be seeing much more of Oogi, or that maybe he will have a larger role in the plot of Book 3.
"The title of Book 3 is going to be called ‘Change.’” “It’s all about Korra dealing with the change of the world in this point in time. At the end of Book 2 she says it’s a new era. And it really is and we’re going to show how Harmonic Convergence and her battle with Unalaq and Vaatu kind of shifted the world a bit."DeMartino also mentioned that their is no set release date as of now for Book 3. However, on the better note, he pointed out that Book 3 is already in post-production progress and is expected to take much less time to air on TV then Book 2 had taken.
