The Outback is a hilly desert-like biome filled with patches of grass, small Acacia trees and shrubs. Most of the surface is covered by hardened sand (1.8), and elevation can vary by about a dozen blocks. As of 1.9, the hardened sand was removed. Grass blocks and red sand is the surface of this biome (1.9+).
Grass can be found on the ground, with a scatter of tiny trees. Survival is a challenge, because the Acacia trees are only two blocks tall, and animals are scarce. However, there is enough wood to make a sizeable house, and wheat can be grown using grass seeds. Desert Temples may spawn in this biome.