Cornelius Dennis "Mad Dog" Madigan (born October 4, 1934, in Port Arthur, Ontario) is a retired Canadian professional ice hockey defenceman notable for being the oldest rookie in National Hockey League history. At the time of his retirement, Madigan was second in minor league history in career penalty minutes, and is still 62nd in that category. In addition to Madigan's hockey career, he had a minor role in the 1977 cult classic movie Slap Shot as legendary hockey goon Ross "Mad Dog" Madison.