Then again, dreams don't have to make sense, right?
Anyway... I was playing on the Dream World yesterday and I saw a Diglett fall off an ice stalactite. It was only for a split-second, but I could see the Diglett in the air with all the earth around and nothing below.
I've caught her and named her Oddity (because Incongruity was too long for the game). She has a Serious nature (no, seriously!) and her stats are quite good for a Diglett, especially her Defense and Special Defense.
Have you had any other experiences that made no sense while playing the games? Diglett-related or otherwise.