Our good friend, Photi at Fish Chunks has the story of the rookies hazing parade, though all of the players involved aren't rookies. But the rookie aspect of the story makes it easier to explain.
You can find the link to the story here: Marlins rookies' hazing parade.
Photi also links to show pictures of the event. Pictures of the parade.
If that wasn't enough, and it really should be, here is a video of the event.
(via Teal and Black)