Philly is a recurring supporting antagonist in the Dog Man series. He is first a minor antagonist in the first Dog Man book, being the secondary antagonist in Chapter 4: " Dog Man In The Weenie Wars: The Franks Awaken" (reference to Star Wars: The Force Awakens). His species is a statue of a gyro. He is named after Philadelphia cheese steaks.
During Dog Man in The Weenie Wars: The Franks Begin, after being brought to life with living spray and betrayed by Petey, the Leader Hot Dog swore revenge on the evil cat. The leader Hot Dog was responsible for creating a hot-dog army starting a revolution to take over the world. However, it didn't go as the living hot-dogs planned, so the Leader Hot Dog brought Philly to life and took him into his army. The two would run into conflict with Dog Man himself during the battle.
After Dog Man freed the other dogs from Petey, Philly grabbed Dog Man. As the Leader Hot Dog taunted the dog-headed cop, Dog Man ate him up before he could finish speaking. This angered Philly and planned to crush Dog Man with his fist. Unfortunately for the gyro, Petey's can of living spray fell into the fire and exploded, destroying Philly and sending Dog Man and Petey flying away. The rest of the hot-dog army got eaten up by the other dogs.
He is a living cheese steak.
The Dog Man Wiki has a collection of images related to Philly. See Philly/Gallery.