"Agreed," said Fred. "So, people, let's try and calm down a bit. Things are bad enough without inventing stuff as well. For instance, this new idea that You-Know-Who can kill with a single glance from his eyes. That's a Basilisk, listeners. One simple test: check whether the thing that's glaring at you has got legs. If it has, it's safe to look into its eyes, although if it really is You-Know-Who, that's still likely to be the last thing you ever do."