Vistani
From SargeInCharge
Basically gypsies, if all the negative stereotypes you ever heard about the Romani were true.
They tell a story of their ancestors helping Strahd when he was being pursued by enemies, earning his eternal gratitude (which could well turn out to actually be eternal if no mischief befalls him) and are the only people permitted to move freely in and out of the fog that surrounds Borovia.