This gentleman got some attention in 2012 for dressing as the Rally Banana in Milwaukee, but here is proof that he was not the first Rally Banana. It's a 2011 baseball card from the Delmarva Shorebirds, Class A affiliate of the Baltimore Orioles in the South Atlantic League. Quoting from their website:
"The Rally Banana emerged in 2011 as a key component in 9th inning rallies. Every time the Shorebirds where trailing by three runs or less heading into the bottom of the ninth, the Rally Banana exploded out of the tunnel and energized the crowd by running around the stadium to "Peanut Butter Jelly Time". The Rally Banana also casts a spell on the visiting team. "
I am not suggesting plagiarism is at play here, but merely illustrating that two people can have the same great idea independent of one another.