PDQ Bach in general:

Little Pickle Book for theater organ and dill piccolos, S. 6
Sonata Da Circo (Circus Sonata) for steam calliope, S. 3
The Only Piece Ever Written for Violin and Tuba, S. 9, 10, big fat hen

and, of course!:

Erotica Variations, S. 36EE for Banned Instruments
(Wind-breaker/Balloons/Slide Whiste/Slide Windbreaker/Lasso
d'Amore/Foghorn/Bell/Kazoo/Gargle [1 player]) & Piano