2. Sidd Finch
Career Years: 1985
Career Lowlight: Proven to not be a real person, crushing hopeful Mets fans.
This one takes the term "joke" a bit literally; Finch was created out of thin air by Sports Illustrated writer George Plimpton in 1985, with the scribe claiming that Finch could throw a fastball 168 MPH, was a yoga enthusiast and only wore one shoe while pitching. When they heard he was in their team's farm system, the poor Mets fans bombarded the front office with calls about this phenom who was going to help their team dominate for years to come. Unfortunately for these fans, the Mets held a press conference on April 2 to announce Finch's retirement, ending the ruse before it could go any further and make the fans seem more pathetic.