Definitely Shoveltusks. Not because they can kill me, but because they've got a horrible nails-on-chalkboard sound they make, and it gets worse in packs.

Well, for comparison...

5000 watts - Electric oven
5000 watts - Clothes dryer (electric)
3800 watts - Water heater (electric)
3500 watts - Central Air Conditioner (2.5 tons)
1500 watts - Microwave oven
1500 watts - Toaster (four-slot)
900 watts - Coffee maker
800 watts - Range burner
500-1440 watts - Window unit air conditioner

In the U.S., heating and AC consume far, far more energy overall than electrical appliances. In fact, the aveage home uses 44% of its energy just on space conditioning.

I guess what I'm saying is, if you want to play Half Life on your enormous rig for four hours, turn off your central AC for one hour.

Or, since one horsepower is 746 watts, plug your computer into a horse!

Having seen it personally, I can confirm it's his invention. He even wrote a simple program in Blitz3D to manually adjust the lighting on the character to match up with the screenshot in the background.

It's rediculous amount of effort to go through for one faked image, but that's his way.