Handcuff yourself to Goofy and yell repeatedly "WE'RE ALL GOOFY GOOBERS YEAH GOOFY GOOBERS YEAH" then throw the key into a bush.
At Christmas go to the giftshop and steal all the keyrings, hang them on your fingers and run around the park screaming at the top of your voice, the song "Jinglebells rock".
If they're having a parade, hijack a float and drive around like a maniac laughing hysterically and crashing it into different rides.