Kill or be Killed is an achievement that you can gain by playing Far Cry: New Dawn. It requires the killing of any monstrous animal.
On the map, you will find several such habitats. In each of them, you will encounter one monstrous animal specimen. You can learn about these locations while exploring or you can buy maps from merchants in exchange for ethanol. However, the second solution requires you to improve the Cartography level in Prosperity to the highest possible level.
Before you can fight this type of animal, however, you must have the appropriate weapons. It's best to possess a weapon from level three or elite. The fight really only seems difficult. This is due to the fact that most of the animal's body is very resistant to injury.
However, each of these animals has a weak spot. It is highlighted in red. You can find them on the belly of the animal. Hitting this place automatically takes more than half of its health. Hence, the fight boils down to just two shots. This requires you to flank the animal. In this case Timber is very useful, which will attract the attention of wild animals after killing a sufficient number of enemies.