She was given Brady's King Ring by her father, the Tarantula Shaman. She then went to the light side looking like a beautiful girl, but Boomer kept Boz from going near her because the 10th Bromandment was to never let a girl come between them. Mary Ann then got Boomer to hug her and Lanny let Boz see it which caused them to fight in the coronation and Boz revealed Boomer's ballet secret.
Afterwards, Mary Ann lured Boomer to a waterfall and ambushed him with an army of Tarantula People. She threw Brady's King Ring off the cliff, but Boz saved him and Boomer defeated the Tarantula People with his ballet skills. Mary Ann then left, telling Boomer he won this one.
Mary Ann later returned to track down the Bat Medallion. She and two of her best warriors followed Boz, Boomer, and Mikayla to Chicago when they went to meet Rebecca's father. Mary Ann and her men captured Mikayla and tried to force Boomer to hand over the medallion. Fortunately, Mikayla escaped and Mr. Dawson used Tarantula powder as a former Tarantula shaman to defeat Mary Ann by turning her into a Tarantula. It is unknown what has become of her since she is last seen being put into a pot in Tarantula form.
Mary Ann has the ability to change her hairstyle instantly, from straight to crazy and vice versa, although this is a normal Tarantula girl power.
She can also eat whole animals in minutes or possibly seconds, leaving only bones. She claims that the brain is her favorite part.