Dunes are sandy desert-Biomes that can be rather hard to find. Still they exist in small amounts on all Creativerse-worlds.
Dunes are merely made of a lot of Sand with Dirt underneath. Sometimes Cacti will grow there, but usually in small numbers, different to Canyons, where Cacti and their useful Cactus Flowers are very common. It's not uncommon for rivers to flow near Dunes, but oases or lakes seem to be very rare in this biome.
On Dunes Shorewood-trees might grow, and on or close to these trees Chizzards will often spawn. Dunes are otherwise inhabited mainly by Rocksters. Near Cacti (or even on these plants), Dustevils and/or Dried Leafies can often be encountered. Also Pigsies might roam around in Dunes, possibly close to Cave-entrances where Dirt can make them spawn.
At night, aggressive Night Rocksters are a common sight in Dunes, and Night Chizzards can show up close to Shorewood-trees. Only rarely Night Leafies might appear close to Cacti, Night Pigsies can occasionally be spotted near Caves, and a Miru or two might come out of caves.