Someone who pointlessly knocks on the door.
Open the door, hand him the cash and take the pizza
Open the door. Put in the elephant. Close the door.
Cause she doesn't have arms. Knock, Knock, Whose there Not Sally...
I went out on a limb.
A visit from the university board of ethics.
A pure bred meth lab.
Dind Dong
Because they don't like random people knocking on their doors
Someone knocking at your door for no apparent reason.
Because they don't believe in higher powers.