This comes from when I was playing Dungeons & Dragons and there was this big monster called the Tarrasque that was suppoedly immune or resistant to tons of different forms of magical and mundane attack. But the rule makers didn’t think outside the envelope and tell us whether it was tickish. Or what would happen if we poured black pepper down it’s nose. Or put a circus tent over it’s head and tried to make it think it was night time like you can with a parrot. Or if you could drown it. Invulnerable my butt!