Pestilentia is the most unique biome currently available in the game. Although resource poor it is rich with various nests and enemies. Of all the biomes this is the most dangerous to explore as the access to certain border areas is limited and usually protected with a nest site. Containing deep ravines, narrow ridges and sharp cliffs it is difficult to travel needing a lot of jumping to move. The weather is often rainy, foggy and dark making it even more treacherous. The nights here are long and the days are short making using the daylight a valuable asset to take advantage of. When deciding to go to this biome insure your Crossbow and Armor are fully upgraded, and that you carry a large quantity of arrows. There is no need for Tranquilizer Arrows because there are no animals to save. While here be patient, observe your surroundings, stay on the sides of the hills and cliffs while traveling and you should be fine. It is a very unusual biome but still fun to explore. Many players put fencing around the nests found on the other biomes to be able to farm them for the resources. Pestilentia is just one huge fenced area. As of a recent patch a large Mutant Factory has been added into the zone. Also various mutant housings have been changed to fit the new model.
Current as of the 2.26patch.