They are a group of pink hostile fairies. They are shown to be aggressive to anyone who they encounter. Despite their diminutive size, they are able to ride their motorcycles perfectly.
Role in the film
The Pixie Dusters are first seen parking their motorcycles at the Swamp Gas area where Ian, Barley, and their father witness them attacking an innocent customer who was unaware of them, causing him to drop his soda. Upon entering, the Pixie Dusters swarm the retail market just as Ian, Barley, and their father walk past them. As Ian notices Dewdrop angrily talking to his late father, the elf brothers and their father manage to escape after paying the storekeeper to avoid getting into a brawl.
Meanwhile, Barley argues with Dewdrop about the Pixie Dusters' inability to fly just as Ian and Barley's father topples over the Pixie Dusters' motorcycles. Just as Ian and Barley escape via Guinevere, the Pixie Dusters chase them across the freeway via motorcycles just as they end up ambushing them. Trying to lose the Pixie Dusters, Dewdrop summons the other Pixie Dusters to take down the the elf brothers and their father to which Ian activates the air conditioner, blowing some of the sprites away. While continuing to chase them, the Pixie Dusters crash into sand barrels, causing them to fly again as the elf brothers and their father escape from the Pixie Dusters.
While Laurel and Corey are on their way to rescue Ian and Barley, one Pixie Duster is seen crashing onto Laurel's windshield, shocking Laurel and Corey along with Colt, also causing them Laurel to crash her van. A group of Pixie Dusters then arrives towards the injured member as they retreat to heal the injured sprite. During the epilogue, Pixie Dusters are seen playing darts in the reopened Manticore's Tavern.