What is the significance of the ';possum'; on columbian masks?

I have just received a mask from columbia as a gift. Curious to know the history and meaning of the mask.What is the significance of the ';possum'; on columbian masks?
It depends a lot on what your mask looks like, I'm assuming you mean pre-columbian here. I found one example of a historical reference to a ';water opposum';, which could be who/what your mask represents:


'; In 1484 the Great Speaker Tizoc (Tee-zohk), He who offers his own Blood to the Gods, laid the foundations for the rebuilding of the ancient temple to Huitzilopochtli. He took prisoners and sacrificed some to the god. The annals say that this was the first sacrifice of human captives on a large scale. In fact it had long been felt to be necessary to kill a few captives, rarely more than 20 at even the greatest ceremonies. Tizoc died before the temple was completed. When the great building was completed, it was to be dedicated by his successor, the Great Speaker Ahuitzotl (Ah-weet-zoh-tl), ***Water Opossum***, a magical creature believed to be the cause of death by drowning. Ahuitzotl was a patron of the arts, and a great lover of music. He had more wives than any other Mexican ruler, and rejoiced in flowers, beautiful birds and animals. Yet his name became a synonym of horror and cruelty. When the great temple was dedicated, he took 20,000 captives and had them all sacrificed in four days by eight teams of priests. The year was 1487, only five years before Columbus sailed into the West Indies. Ahuitzotl died in 1502 when the Spanish had just settled in Cuba. His successor was Moctecuzoma Xocoyotzin (Mock-the-koo-zoh-ma Shoh-koh-yoh-tzin), Prince Strong Arm, the Noble Lord.';