Amadea is correct. I have had appearances by Petey the Panther from FIT and DJ Kitty from the Tampa Bay Rays in full on mascot costumes. You may get hot in the suit, but costumes are totally allowed. (I have even run karaoke in a full Darth Vader suit)
As long as the basics are covered (shirt, shoes etc), and it's not political, you'll be fine wearing whatever.
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