Oh no, that’s a tough one.
OK, I have two that are tied for first place. The fist is a refrigerator magnet of the Monorail and when you push a button, it plays the “Por favor mantenganse alejado de las puertas.” I love it!!!
The second is a tiny fake camera with a view hole and when you click the lever, it changes to a photo of a different park. Sort of like a Viewmaster, which was my favorite toy as a kid.