Ix Chel (sometimes spelled Ixchel), the moon goddess, is one of the most important ancient Maya deities, connected to fertility, and procreation. Her name has been translated as “Lady Rainbow”, or as “She of the Pale Face”, alluding to the moon's surface.

Although not directly mentioned in colonial sources, in the codices Ix Chel appears in both old and young variations, to whom Maya religion specialists attribute respectively the names of Goddess O and Goddess I. As an aged woman, Ix Chel is usually portrayed with a serpent headdress, a skirt adorned with crossed bones, and jaguar claws instead of hands. It has been proposed that the two variants correspond to different aspects of the moon: the old Ix Chel is connected with the full moon, and its waning aspect, and the young Ix Chel is connected with the crescent moon. This interpretation is partially supported by some Classic period depictions of the young goddess sitting on a crescent moon, holding a rabbit.

According to ancient Maya mythology, Ix Chel was the wife of the god Itzamna, and they were the progenitors of all the other gods.

Source: http://archaeology.about.com/od/mayaarchaeology/a/Ix-Chel.htm