Well there's the Fartophone, but I'd rather not go into that.

Then there is the rather unpleasant Squelch Cymbols, which comes in different sizes. The creature who supplies the "squelch" as the cymbols crash together can be a canary, a hamster or a chicken. Or in one version a male volunteer from the audience is involved, but that is another topic where the details are better shrouded in obscurity.

Fortunately both these instruemnts are specifically banned under the new Licensing Law in England. It had to get something right, I suppose.