Mrs. Hardenbauer is a senior citizen who often became entangled in the paranormal in 1997.
Mrs. Hardenbauer's husband was one of many infected by Achira. As she tried to tend to him, the disease left the husband soon after the Extreme Ghostbusters trapped her. Some time later, she noticed something was off about her husband. He lurked for the first time in his life. Mrs. Hardenbauer called the Extreme Ghostbusters and explained her concerns. However, they were unable to locate Mr. Hardenbauer and concluded it was false emergency. Janine Melnitz thought of charging her with a three story spectral inspection but threw in a senior citizen's discount.
Mrs. Hardenbauer purchased produce tainted by Ravana from Jon's Groceries. She became infected by the high band P.K.E. and began gorging on food. She even stole an ice cream cone from a boy. Eventually, she was rounded up and taken to Memorial Hospital. Some time later, Ravana fed on her and its other victims. Once Ravana was captured, they all reverted to normal.
- On page 19 of Ghostbusters Volume 2 Issue #5, Mrs. Hardenbauer makes a non-canon cameo as the woman waiting for the elevator.