Ninja! Trophy in Hunter's Trophy 2: Australia
While stalking, do not get spotted by a big game animal
How to unlock Ninja!
This is easiest to do in your first big game hunt titled “First Big Game Hunt” in Hossack. Simply do not allow the animal to see you. You can press to zoom in on your radar and see the direction of where the animal is looking. It is very easy to get very close to the animal without it even knowing. Just stay crouched and out of its line of sight.