Go to the Mario level with the pipes and the platforms in the middle (I forget the name...) as Yoshi and somebody else. Now, make Yoshi stand by a pipe and put the other person on top of the same pipe. Now, make that person go down the pipe, and just as they're about to enter it, make Yoshi eat (B) the person. If timed correctly (make Yoshi lick a little early), Yoshi will swallow the person and turn them into the egg. Even though they never entered the pipe, the pipe sound will play.