George "Zip" Zabel did not have a particularly long or prolific career playing major league baseball. The pitcher played only three years for the Chicago Cubs from 1913-1915 before arm troubles bumped him back down to the minors and eventually out of the league entirely. But he did not exit the game without leaving his mark.
On May 17, 1915, Brett Humphries was starting for the Cubs against the Brooklyn Dodgers. He gave up one run in the first after getting the first two outs, so manager Roger Bresnahan yanked him in favor of Zabel without giving the latter the chance to warm up. The game ended up going 19 innings. Zabel pitched the whole way through, officially giving him 18 and one-third innings of relief, a MLB record.
Over the course of those 18 and two-thirds innings, Zabel gave up only nine hits, two runs, and an intentional walk. He effectively threw two complete games in one sitting, an impressive feat matched only by the pitcher he was facing that day, Jeff Pfeffer, who started for the Dodgers and pitched all 19 innings. The Cubs would eventually walk Pfeffer off in the bottom of the 19th inning.
Zabel would end up out of baseball by July 1917 and became a chief metallurgist for Fairbanks Morse in Wisconsin. But he'll be remembered for his one legendary relief appearance, and having one of the better nicknames in baseball history.