Impaled Garden Gnomes.

He must have had a pretty traumatic experience with a garden gnome when he was growing up. Instead of going through all of this trouble he should have just downloaded Hammer-Heads off of Pop-Cap games. It would have been a much easier, and less disturbing, way to get out all that pent up aggression.

Ah, the obvious Red Dwarf reference.

And let that be a lesson to all the rest of you mischeveous gnomes.