You'll be doing a lot of things with Assassin's Creed 3 protagonist Ratohnhaké:ton - like chasing down Redcoats and murdering them, running away from murderous Redcoats, sneaking up to silently murder Redcoats, and engaging in open battle with Redcoats. Beyond all that, however, you'll also be fighting terrifying, wild bears, as the trailer above implies. Thankfully for you, we can confirm it: yes, you'll be fighting the bear seen in the above trailer.
The gameplay trailer for Assassin's Creed 3 - unlocked by the community this morning - shows the first Connor-on-Bear action we've seen. It also gives a first glimpse at the game's new "chain blade," but the most important part is still dude fights a bear.