Vilce's name was created from Latvian "vilkt", which means "to pull".
Usually talked of as a female, her actions would be much like those of the pūķis, only she will bring the treasure to you by pulling it from your neighbours and thus causing them to loose their own wealth.
Vilce can be created from an egg, that has been kept in your pocket for about 3 years. Once hatched, she would go on hunt at night, and her appearance will be a bolt of lightning. It is not clear, on what should she feed, but her menu could be similar to that of the pūķis.