You can keep your Bluetooth-enabled smart door lock, we’ll take this as our entry method of choice any day. The Skull Doorknob is a demonic way to cross the threshold of your lair. Crafted by Forever Fineness, the Skull Doorknob alerts guests that you mean business more so than any “Beware of Dog” sign ever could. The company hand makes custom pieces, so you’d have to contact them if you wanted to toss this up on your door, however. Still, it’s more devilish than anything you’ll find at your local hardware store.