Early in the episode, Urkel's doll gets struck by lightning and comes alive. The doll, "Stevil," talks in a satanic voice and informs Urkel that he is going to murder the Winslow family. And then he totally fucking does it: He sucks Eddie into the chimney, runs down the kids in Urkel's car, dismembers Laura and hides her body parts in the cupboards, and finally decapitates the mom and turns her into a goddamn jack-in-the-box.
Which is a legitimately impressive achievement for someone with rigid plastic fingers.
Urkel is relieved to find Carl in one piece and tries to explain what happened, but realizes that the man is sounding a little weird -- at this point, Carl falls to the side, dead, revealing that Stevil has been using him as a human puppet.
We really hope he cut open a new hole to do that.