Ever the opportunists, some lawyers built their careers by defending animals. A sixteenth-century French jurist named Bartholomew Chassenée made his name as the counsel to some rats who were accused, in an ecclesiastical trial in Autun, of decimating the area’s barley crops. Rats being rats, Chassenée could hardly rely on his clients’ sympathetic qualities to get them off the hook. So, like numerous lawyers before and since, he built his argument on technicalities: the defendants couldn’t be expected to appear in court, as Evans says, "owing to the unwearied vigilance of their mortal enemies, the cats, who watched all their movements, and, with fell intent, lay in wait for them at every corner and passage."
I wouldn't be hugely surprised if this were partly apocryphal, but such trials did occasionally happen, and it's a funny story either way.