Long, long ago, the shape of Guam was very different from what it is now.   As you know now, the island of Guam looks like a large foot, being narrow in the middle and large at both ends.

But in the old days, it looked different.   There was a group of happy people who lived on Guam in the old days.  
But at one time, they became weak and unhappy as a result of intermarriage and tribal disunity caused by the influences and evil ideas of newcomers to the island.

Along with the other hardships which bothered the people, a huge fish started destroying the island.  Each evening the fish would come out of hiding and begin eating the middle part of the island.
Everyone on the island felt that there was no way of stopping the monster fish that could neither be found nor destroyed.

Then, from nowhere, appeared a woman who said she was known as the Virgin Mary.   In due time, the woman caught the monstrous fish with her hair and tied it up for everyone to see.
Because the Virgin Mary saved the island from the giant fish, the Chamorro people look upon her as their protector and call her Saint Mary. She is known for her blessings upon the island in time of trouble and need. She is considered to be the blessed protector.