Preheat your grill or skillet over medium-high heat, and shape the ground beef into four evenly-sized patties. Season with salt and pepper, then place them on the hot surface. Cook for about 4-5 minutes per side until the patties are nicely browned and cooked through.
While the patties are cooking, prepare the cheese to resemble monster teeth by cutting slices into jagged mini-shapes. Slice black olives into small rounds for eyes, and cut carrot pieces into small strips or circles for tongues or additional features.
Once the beef patties are cooked, place each on a baking sheet, and top with a slice of cheddar cheese. Broil briefly just until the cheese melts and begins to curl slightly around the edges, about 1-2 minutes.
Toast the hamburger buns lightly until golden, then spread a little mayonnaise on the bottom buns for added flavor and stability.
Assemble each burger by placing a lettuce leaf on the bottom bun, then carefully set the beef patty with melted cheese on top. Use ketchup and mustard to draw jagged monster mouths and tongues on the top bun if desired.
Add the decorated features—olive slices for eyes, carrot pieces for tongues or eyebrows, and the jagged cheese for teeth—on top of each burger to create facial monsters. Secure with additional condiments or toothpicks if needed.
Top each burger with the upper bun, pressing gently to set all the festive features in place. Serve immediately to enjoy the fun expressions and textures.
