In a large bowl, combine the cooked chicken, crumbled bacon, ranch dressing, sour cream, shredded cheddar cheese, garlic powder, and black pepper. Mix well.
Spread the tater tots in a single layer on the bottom of a 9x13 inch baking dish.
Pour the chicken mixture evenly over the tater tots.
Bake for 35-40 minutes, or until the tater tots are golden brown and crispy, and the casserole is heated through.
Let stand for a few minutes before serving.
Notes
This casserole is best served hot. You can add other vegetables like broccoli or corn if desired.