Prepare the Meatloaf:

1. Preheat the Oven: Preheat your oven to 350°F (175°C). Line a baking sheet with parchment paper or lightly grease a loaf pan.
2. Mix Ingredients: In a large bowl, combine the ground beef, breadcrumbs, Parmesan cheese, chopped onion, minced garlic, eggs, milk, Worcestershire sauce, Italian seasoning, salt, pepper, and paprika. Mix until well combined.
3. Shape the Loaf: Transfer the meat mixture onto the prepared baking sheet. Shape it into a loaf, then form the front end into a snout to resemble a rat.

Bake the Meatloaf:

4. Bake: Place the meatloaf in the oven and bake for 1 hour, or until the internal temperature reaches 160°F (70°C).

Prepare the Topping:

5. Add Topping: In a small bowl, mix together the ketchup, brown sugar, and mustard (if using). Spread this mixture over the top of the meatloaf for a flavorful glaze.

Decorate the Rat Loaf:

6. Add Features: Once the meatloaf is done baking, remove it from the oven and let it cool slightly.
   • Use black olives for eyes by cutting them in half and placing them on the snout.
   • Slice pepperoni for ears and place them on top of the loaf.
   • For the tail, shape a piece of pepperoni or use a thin strip of cooked bacon and place it at the back.