Dune Sprites

Of all the stories told, it's the ones that mention Dune Sprites which hold the children enthralled. They begin innocent enough with the sprite minding their own business doing spritely things and might even be one of those cute bed-time stories. That is, until something angers the sprite. This is up for invention by whomever might be creative enough. Parents like telling stories about vengeful Dune Sprites upset that a child stole and ate a cookie. They'll name it Sam which was the Sprite's best friend. Then for a while any misfortune the parents may wag a finger at the child and say "If only you'd listened and not made the Dune Sprite mad."
Conversely, if a child does good deeds they might tell a story about a thankful Dune Sprite which leaves little gifts of thank you.
Some of these stories evolved and taken lives of their own. One such example is the sprite which steals children's teeth in payment for wasting food or water. It makes jewelry out of the teeth that rattles when it comes near. One particular story is about a mutant from the deep wastes who led an army of more of the twisted humanoids, bent on the total subjugation of the planet. Nothing seemed to hurt it. A few brave settlers made a deal with the tooth sprite to buy back one of the mutant's own teeth which was set into a bullet. The would be dictator was shot and immediately died, the army scattering.
Another story relates how a child saw one of the dune sprites, and it begged the child to never speak of it. For a long time the child kept the secret and although never saw it again, sometimes left trinkets out for it and the sprite would trade other trinkets. Until the day the child was teased for believing in the sprites and told his tormetors that it would be proved. A trap was set, not to catch the sprite, but to trade something. The child left a small cubic stone in a prominent place and let the bullies examine the room. They left and came back an hour later and a rubber ball was in it's place. The child called out in exoneration, and the sprite knew the promise wasn't kept. The trades stopped. Some years later the now adult was exploring a wreck in the desert and became lost because the sprite had stolen the needle from the compass. The sprite appeared once more as the person gasped for water, and just sighed and dropped the compass needle in the sand next to them.