Desert

The Desert is a sandy area that spawns desert monsters, cacti, and waterleaf. Each map will generally contain at least two desert areas. Drained Oceans also become deserts. As of update 1.2, pools of water in the Desert biome take on a sandy yellow color. Pyramids are rarely created during world generation in Desert Biomes.

Contents

 * Note: Additional desert items can be found in pyramids.

Desert variations
Deserts can be corrupted, "crimsoned", or hallowed. All of these will be very similar to their main biomes (e.g. The Corruption or The Hallow): the music theme is the same, the mobs are the same (excepted the Dark and Light Mummies), and the background is just slightly different.

The sand will be replaced by ebonsand, crimsand, or pearlsand. Although their color will change, cacti still drop cactus when cut, and waterleaves are also able to grow on hallowed desert.

Hardmode
During Hardmode, the increased spreading of the Corruption/Crimson and Hallow is likely to (at least eventually) convert any normal deserts. Corruption/Crimson deserts spawned upon world creation may also be turned into Hallow ones if they are inside the world part that is instantly "Hallowified" at the beginning of Hardmode. Mummies will start to spawn, and converted deserts will become much more dangerous due to their respective Hardmode-monsters.

Making money
If a player is desperate for money, deserts can be a good indirect source. Sand blocks can be crafted into Glass, which can be crafted into Mugs, which are filled at a Keg to produce Ale, which has a sell price of 20 Copper Coins each. Though the sell price is low, this is one of the only sources of coins in the game that is always readily available, as all other abundant block types cannot be crafted into sellable items without other ingredients.

Assuming the player carries only a Pickaxe and one other Weapon for fighting off any enemies encountered, while keeping all other Inventory and ammo slots available for sand collection: 41,958 sand blocks (42 slots x 999 max sand stack per slot) = 20979 Glass blocks = 20979 Mugs = 20979 Ale x 20 Copper Coins each = 419,580 Copper Coins, or 41 Gold, 95 Silver and 80 Copper Coins.

Trivia

 * Despite perhaps some irony, rain will occur in deserts just as in any other surface-biome.
 * Deserts are one of three (The others being the Ocean and the Mushroom biomes) non limited biome to not have it's own unique Slime.