Mayahuel is an Aztec fertility goddess and goddess of the maguey plant, which produced the intoxicating drink pulque. This drink was sacred to the Aztecs and used in many rituals. The maguey plant was spiny, and priests would use these spines to commit ritual suicide.
Like most Aztec myths, the story is pretty rough. Taken from "Aztec and Maya Myths" by Karl Taube:
Although humans had been provided with seeds from which to make food, there was little in their lives to inspire pleasure or joy. The gods conclude that something is needed to make people sing and dance. Quetzalcoatl decides that intoxicating drink will bring pleasure to people's lives, and he recalls Mayahuel, the lovely goddess of maguey, who lives in the sky with her fearsome demon grandmother. Finding the virgin Mayahuel asleep, Quetzalcoatl wakes her and persuades her to descend with him to earth. There they join themselves into a great forked tree, with Quetzalcoatl as one branch and Mayahuel as the other.
Awakening to find Mayahuel missing, the enraged grandmother calls upon her fellow star demons to help her locate the errant girl. The furious demons dive headlong from the sky to the tree where the lovers are hidden. Just as they arrive, the tree splits apart and the branches fall to the ground. The grandmother demon recognizes the branch as Mayahuel and, savagely tearing it apart, she passes part of her granddaughter to each of the demons to devour. But the branch of Quetzalcoatl is left untouched and unharmed, and once the star demons return to the sky, Quetzalcoatl returns to his actual form. Sadly gathering the gnawed bones of Mayahuel, Quetzalcoatl buries them in the earth, and from this simple grave grew the first maguey plant, the miraculous source of pulque.