In Lithuanian folklore, an aitvaras was a dragon-like household spirit believed to bring wealth or stolen goods to its owner.
An aitvaras was often described as a flying supernatural being that could appear as a fiery or glowing serpent, dragon, bird, or meteor-like object. It was associated with a household and might deliver grain, money, or other valuables, sometimes taking them from neighbors. This made the spirit both useful and dangerous in traditional stories.
Descriptions vary by region and source, so the aitvaras is not identical to a large fire-breathing dragon from medieval European art. It is also distinct from a kaukas, another Lithuanian household spirit often associated with helping or treasure. The aitvaras belongs to Baltic folklore and is especially connected with domestic prosperity, night skies, and morally troubling wealth.