I have a cool idea. Desert/Ashlands could be an actual biome. Sand Slytherers (Big, tan snakes). You must have poison resistance to win a fight against them.Skeletons could also be found. Sand crawlers that crawl across the sand. Villages with Desert Imps. You could find them near dead trees or another biome. Find buildings with maps that show treasure where you can get a shovel and dig for a chest filled with amber, gold coins, rubies. Or not even a chest. Maybe a gold deposit. Speaking of Gold, you can make a coin press to print coins with gold bars, or make gold armor.
Sand trolls could even be a thing. If there even is gonna be a new armor from the Mislands or where ever else, we need a short sleeved armor. Like gold too. If you stay in the Desert for too long in Wolf Armor, etc, you die from heat after a short period of time. You can find Deserts near Plains, Mistlands, or Swamps.
You can get funky cactus armor by cutting a cactus with nothing less than a Bronze Axe in two or three swings. You can purify cactus water if you build a filter. The water helps with heat and stamina. Cactus pricks could be collected when cutting a cactus. You can upgrade pricks on your armor to do 5 damage to monsters that touch you.
The boss is a giant centipede that can smash onto you, whack you with it's tail, summon sand crawlers, and even crawl under ground and attack you from under. You can see where the centipede is going when a small, moving dune is charging at you. I don't know what the boss should be called but make it cool.