After killing my first dragon and gaining a few levels, dragons didn't stopped from swooping down on me. They were everywhere. I don't know if that's how it supposed to be or one of the several bugs the game has. But I couldn't throw a rock without hitting one.
Then, I noticed these mammoths strolling around and I got close, and they attacked and couldn't move and got trampled.
Then I saw the giants, charged and they one hit me up to the skies.