Jeffrey Leonard
The 1987 National League Championship Series between the Cardinals and the San Francisco Giants was a seven-game thriller. Despite Giants outfielder Jeffrey Leonard's best efforts, the Cardinals won the series, but not before Leonard had become an enemy in St. Louis because of his "one flap down" home run trot.
Leonard, who hit a home run in each of the first four games of the series, would embark on a slow, deliberate jog after hitting a big fly while keeping his left arm down by his side. Cardinals fans did not react well to this, booing Leonard as he took his position in left field. Leonard's continued success and subsequent "one flap down" jogs increasingly incensed Cardinals fans, and after Leonard's third home run, Cardinals pitcher Bob Forsch sent a message, plunking him with a pitch.
In Game 6, Cardinals fans were so fed up with Leonard's unique celebration and teammate Chili Davis' remark of St. Louis as a "cow town" that they hurled items at Leonard from the left field seats, including coins and frozen hot dogs, and forced the game to pause on two separate occasions.
There weren't many more chances for the hate to reach Leonard personally, as he only played two more games at Busch Stadium in his career before spending the rest of it in the American League. But fans who saw that series undoubtedly remember Leonard's performance and his showmanship.
Cardinals fans understand and appreciate the game of baseball, but there will always be players who aren't remembered fondly. Despite the reputation as the best fans in baseball, Cardinals fans aren't immune to having players get under their skin.