Aatxe is a spirit from Northern Spain and Southwest France, specifically in the Basque region. This spirit can take the form of a man, although appears to prefer the form of a large red bull. Some sources say that he is a master shapeshifter who can change his form at will. Aatxe lives in caves or other hollows, although according to the Auñamendi Eusko Entziklopledia, Aatxe only lives in Sara’s cave in Lezia. He is the guardian of the cave and will attack those who offend him.
Aatxe is known to protect innocents in poor weather, attacking criminals and those with ill-intent. The spirit encourages those who are innocent to remain home while he hunts those who are malicious. He is also linked to the goddess Mari.
In current media, an Aatxe is an enemy in the game Guild Wars.