In 1805, when George Gordon Byron, 6th Baron Byron, commonly known as Lord Byron, became a student at Trinity College, Cambridge, the college told him that he could not have a dog, so he got a bear from a traveling menagerie instead, arguing that since bears were not specifically mentioned in the college's statutes, the college had no legal grounds for complaint. Byron won the argument, and he walked the bear around the campus as if it were a dog.
In more recent times, a Russian employed the same ursine loophole when authorities attempted to fine him for his pet bear defecating in front of a local newsstand. Robert Biryukov argued that his bear cub was exempt from the law, which only applied to dogs, and he got off with nothing but a warning as a consequence.
Meanwhile, back at Cambridge, dogs are still banned, but cats are not. What to do if you want to keep a dog? Roger Mosey, a master at Selwyn College, Cambridge University, convinced authorities his Bassett hound, YoYo, was in fact a large cat, citing a precedent from approximately 50 years earlier.