No complete scripts exists for this cancelled episode. This is how the plot would've gone:

While fetching supplies for ZIM, GIR gets hit by a truck. Some scientists witness this event and are amazed at how GIR is fine after the accident. They abduct him for their "ultimate doggy" experiment. They decide to combine GIR's strength with the obedience of another dog. While getting a sample of GIR, they only retrieve a bit of doughnut crumbs. They unknowingly create a horrible doughnut-dog monster. A scientist then helps GIR escape.