This was passed on to me by a colleague. Original source appears to be from W. Fred Rump from a German geneology list.

A cat flap is called a cat flap because they are designed for use by cats as opposed to dogs, giraffes or humans. They are relatively small openings in doors of houses that let the cat go in and out at leisure.

In Germany, Gunther Burpus remained wedged in his front door cat flap for two days because passers-by thought he was a piece of installation art.

Mr. Burpus, 41, of Bremen, was using the flap because he had mislaid his keys. Unfortunately he was spotted by a group of student pranksters who removed his trousers and pants, painted his bottom bright blue, stuck a daffodil between his buttocks and erected a sign saying: Germany Resurgent, an Essay in Street Art. Please give generously.

Passers-by assumed Mr. Burpus screams were part of the act and it was only when an old woman complained to the police that he was finally freed.

I kept calling for help, he said, but people just said Very Good! Very Clever! and threw coins at me.