Stop by any "box store" (Home Depot, Lowes, Wal-Mart) and pick up a pair. The big ones come in a box of two for about $12 ? Mine were about 3 feet? long and had a big flat auger style end with an eye hook on the other.

If you can get that bad boy sunk in all the way to the eye, I doubt anything will pull it out. I'd get a 1/2 broom handle to use for leverage (put in the eye) to screw the thing into the dirt.