Amid the ever-changing chaos of Limbo is an area where a jumble of alabaster boulders and rocks tumbles through the miasma, crashing into one another and anything else in its way. The boulders seem to be drawn to a central point of gravity. More than anything, they look like a great maw of teeth chewing up everything in their path.
This phenomenon is just a part of the unpredictable nature of Limbo - the goddess Yondalla has nothing to do with it. The place earned its name because acrobats and tumblers from all over the multiverse travel to the Teeth in order to hone their prowess at avoiding injury even in the most chaotic of circumstances. A disproportionate number of these visitors are halflings, and so it became widely, albeit erroneously, supposed that their goddess had something to do with it.
Anyone spending time within Yondalla's Teeth suffers damage from the tumbling boulders. However, it is a planar touchstone site, so visitors are willing to test themselves to receive its boon.