Huntress – Kill 50 animals while wearing the Huntress outfit

Firstly you need the Huntress Outfit, you get it as a Reward for completing the Mission A Hearty Meal, then equip Outfit in a Basecamp. A good place to kill 50 animals is here in the Geothermal Valley, since the chickens and birds respawn almost immediately.

other Rise of the Tomb Raider Achievement Guides

AchievementDesc.
No Stone UnturnedAchieve 100% game completion
Bacon
Quite TImeFind the best seat in the house