I was experimentating with the theme objects function when I noticed one of the terrain objects transformed into something very familiar:
http://s177.photobucket.com/user/ajbckmn/media/Disney%20Infinity/WIRstump_zps9724c59f.mp4.html
The name of the Object is Fantasy Terrain 2, found in the Plants object section.
The theme is Niceland Terrain 3.
And here is a picture of it after it changes into Ralph's stump:
A warning, once you "theme the object", you won't be able to select it with the magic wand or spark!
So consider it's placement very carefully before theming it.
I think this is a variation of the bug that affected the Frozen objects.
Now I am wondering what other familiar objects may be hidden in the game like this one.