I don't really remember tbh, I just remember fliping to 3d to dodge him a bit then you end up on his back and have to make your way to his head. I don;t remember having any trouble with it. You are using the correct pixel arn't you? I don't think you have many that early in the game.
Personally I don't like Wii games too much, but the ones I do play seldomly are: Wii Sports Super Mario Bros
Now i'm having trouble in super paper mario with the 100 levels part, that shit is really tough. I almost feel as if I have gone to that part to early, are there certain pixies or items that make those 100 mini levels easier? Current pixis are the bomb, the one that grabs guys for you, and the one that makes you really skinny. I pratically only use the bomb on that is their one that is particularly good for like ghosts and the ones whose heads you can't jump on?