Preheat oven to 350 degrees F (175 degrees C). Grease a 9x13 inch baking dish.
In a large bowl combine whole corn, cream-style corn, sour cream, egg, dry corn bread mix, onion and 3/4 cup of Cheddar cheese. Mix well and pour into prepared dish.
Bake in preheated oven for 25 minutes.
Remove from oven and sprinkle with remaining cheese. Bake for another 20 minutes.
