Epcot has a lot of spots for training, making it a good park to meet some unusual characters. While it’s all random and unscheduled, with a new CP in session and preparation being made for Mickey’s Not-So-Scary Halloween Party, it’d be worth a try to meet some characters you wouldn’t normally see in Epcot! (I’ve seen a few posts in the Epcot tag over the last few days of people meeting Dr. Facilier, which would have to be an entertaining meet-and-greet.)
To read more about these areas, I recommend KennyThePirate’s Unofficial Disney Guide, which has lots of information on when/where you have your best chance at meeting a rare character! Also, enjoy this video with one of the most random line-up of characters that I think you could ever hope to meet.