The Ocelot Armour one of the new drops added with this DLC. It can be found commonly in chests in the DLC areas or you can purchase it from the merchants at camp when you have the DLC installed.
With all the Ocelots you may think this difficult, but this trophy can actually be obtained in the Panda Plateau mission. There are in fact, zero ocelots in the Panda Plateau mission, but it is still possible to obtain. You just have to make sure you have the Ocelot Armour equipped before the mission begins and that you don't take it off.
Assuming you leave it on for the whole mission, you will obtain the trophy during the loading screen after completing the area.