Michelle is a school mascot in Cottage Grove, Minnesota.
Michelle attended high school in Cottage Grove, Minnesota where she became the school mascot at some point. She had Phil Evans as her PE teacher for one semester.
One night while trying on the new mascot costume, Michelle became possessed by the vengeful spirit of Chester Johnson, the costume's previous owner. Wanting revenge upon Phil for Phil's role in his death, Chester used Michelle to grab a weight and begin bashing in Phil's head. Noticing the attack, quarterback Brock Buckner rushed in to restrain Michelle. Despite Michelle being scrawny, Chester was able to increase her strength to match that of the immensely strong Brock. However, Brock eventually subdued the possessed Michelle and she was taken into police custody.
After learning of cold spots in the weight room during the attack, the Winchesters were able to determine that they were dealing with a case of ghost possession. In order to free Michelle, Dean Winchester blasted her in the chest with a shotgun loaded with rock salt shells. The rock salt expelled Chester from Michelle who retained no memory of her possession and was confused to wake up in a jail cell.
The Winchesters and Sheriff Donna Hanscum questioned Michelle about the jester costume's origin and she was able to identify it as being donated by Rita Johnson. At Sam's suggestion, Donna let Michelle "escape", claiming that the attacker was a drifter who overpowered Donna and escaped without Donna ever seeing the drifter's face.