Grate the zucchini and carrots and set aside. In a large mixing bowl, stir together the Bisquick™, salt, garlic powder, and black pepper. In a separate, medium bowl or large measuring cup, whisk together the eggs and milk. Pour into the bowl with the dry ingredients and stir by hand, just until combined. The batter will seem very thick, but the water from the zucchini will thin it out slightly.