Darth Maul pencil
When you make so many mistakes that your pencil eraser has diminished, therefore making that side of the pencil useless. UNLESS you break off the metal and proceed to sharpen the once eraser side of the pencil, making it into a double leaded, or Darth Maul pencil. Refers to Star wars episode 1 when Darth Maul is shown with a double headed penis-- i mean lightsaber.
Damn, my eraser's gone, might as well make this a Darth Maul pencil.