Some events are so important that they remain famous centuries, even millenia afterwards.
Nero and
Caligula were
Roman emperors, so they lived way before the Salem trials, but thousands of years later these two names still have extremely negative associations, being almost synonims for "mad and bloodthirsty tyrant".
Everyone who's got a minimum of formal education will know about the Salem witch trial. It's a bit odd to be bothered by a TV programme and not by history, and incidentally I assume the name was picked for the character of the cat just because of the "witchy" connotation.