During his tenure as a Georgetown faculty member, Pilarz became involved in a movement to revive the university's Jack the Bulldog live mascot called "Bring Back Jack." In 1998, Pilarz collaborated with three students and co-founders of the Hoya Blue fan club – Michael Boyle, Austin Martin, and Kathleen Long – to bring back the bulldog mascot tradition at Georgetown. The Hoya Blue club and the senior class raised $1,500 to purchase Jack, Georgetown's first live mascot since the 1970s. Pilarz personally picked up the new Jack the Bulldog, who was named John P. Carroll then a nine-month-old puppy, upon his arrival at Washington Dulles International Airport on February 16, 1999. Pilarz became Jack's caretaker and roommate at Georgetown. He would walk Jack in the mornings and evenings while student volunteers walked the bulldog mascot during the day while Pilarz was in class or other university functions.