Colombian drug-lord pablo escobar kept four hippos in his estate before his death in 1993. Deemed too much hassle to move by authorities, his hippos were left there and have since bred and escaped becoming an invasive species of colombia.
Beethoven kept a diary of his day-to-day goings on when living in Vienna from 1792, giving us insights into his daily life, from finding a new wig-maker to finding a place to buy a piano.