Okay. It was a very strange way to do it, though.
You first lick up one of the shy guys that come from the pipe. Next go over to the highest point: the breakable stuff above where you get the key. Spit the shy guy onto this (by jumping away from it, facing towards it, and spitting upwards). Then do a high jump-flutter off of the shy guy, and off of the top of the screen. If you can then continue to flutter without losing moch altitude, you can make it over the wall, off the top of the screen.
A bit strange, but it works.
And I haven't thought of a question yet. I'll make one later.
Go Moon!