"Dippy" McDoogun was a criminal accomplice of Steve the Tramp. He had dark hair and a round face.
Steve the Tramp had kidnapped Junior Tracy and taken him across the country to Hank Steele. During the course of their journey they came across an old associate of Steve's called "Dippy" McDoogun. Steve and Dippy stole a handcar from two railroad workers at gunpoint.
Train meets handcar
Continuing west, the three found themselves on a railroad trestle over a river when a train came toward them. Junior and Steve jumped into the river and swam to safety. The train struck the handcar at a high speed, knocking both the car and McDoogun into the river. McDoogun (who had stated that he could not swim) was presumably killed, but Steve and Junior did not look for him.