300: Rise Of An Empire (2014)

All horseback riders were stunt riders or experienced actors who were skilled at riding, mounting and dismounting. All running/galloping scenes were well choreographed, and actors used caution while on and near animals. The horse(s) rearing was a trained behavior.

After the opening battle scene, we see men on horseback retreating and a horse is seen stomping on a soldier. For this scene, the trainer stood off-camera, then cued the horse to rear back, then stomp on the ground.  The scene was filmed in front of a green screen, so we assume that the soldier was created in post-production.

For some of the horseback riding scenes (including the horse on the ship), the elephant walking in the background and the crow pecking, these were all done in post-production through CGI.