The Ulterior Outback is one of the most dangerous biomes in the entire Erebus, and possibly even surpasses Volcanic Deserts in terms of danger.
It is not advisable to set up camp in the Ulterior Outback, unless you plan to commit digital suicide or are some kind of hardcore adrenaline junkie. Seriously. Even Volcanic Deserts are a better option in terms of mobs alone.
Comprised of Red Sand, Dirt and patchy Grass, this biome is fairly inhospitable for plant life, although Fireblooms can be found here. Hollow Acacia Logs can rarely be spotted.