Preheat your grill or grill pan over medium-high heat and brush lightly with vegetable oil to prevent sticking.
Divide the ground beef into four equal portions and gently shape each into a thick patty, about 3/4 inch thick. Press a slight indent in the center of each to help them cook evenly.
Season each patty generously with salt and pepper on both sides and place them on the hot grill.
Cook the burgers for about 4-5 minutes per side, until they develop a nice brown crust and are cooked through, with juices running clear.
During the last minute of grilling, place a slice of cheddar cheese on top of each patty and cover to help the cheese melt beautifully.
While the cheese melts, cut the black olives in half to create creepy eyes, and slice the cherry tomatoes for extra facial details or decoration.
Remove the burgers from the grill once the cheese is gooey and the meat is fully cooked, and let them rest for a minute.
Assemble the monsters by placing each burger on a plate, then decorate with the olive eyes, cherry tomato accents, and optional lettuce to create whimsical monster faces.
Serve immediately while the cheese is gooey and the burgers are hot, with extra lettuce or buns on the side if desired.