Before our first trip with our oldest boys, we tried to introduce them to other costumed characters beforehand, anywhere that we could- the zoo when Scooby-Doo or Ronald McDonald was there, Chuck E Cheese, even a trip through a local costume shop. They had no problems with any of this, and absolutely loved the Disney characters. With the toddler we have now, we recently visited a local amusement park to see Porky Pig and others, to test him out, as well as took him up to see Chuck E Cheese during a birthday party. He doesn't like them at all! I'm going to keep doing these little introductions, but I can see him not being fond of Mickey or Pooh as well.