See that boar? It's not in the official game. Not yet.
But it is in the Unstable Branch...
This branch contains the latest, experimental content; it is updated more regularly than the official branch. However, it is not as thoroughly tested as the official branch, and it will not allow you to start daily or weekly runs (as these might be different).
If you are interested in seeing where the game's headed, and don't mind helping us out finding bugs and balance issues you can switch to this branch. And don't worry, you can always switch back.
To switch to the Unstable Branch you need to right click on Unexplored in your steam library, click properties, and select the Unstable Branch from the beta tab:
One more thing. If you do opt in to the Unstable Branch, please report any bug or discuss its content at the special forum section.