Preheat the oven to 375°F and line a baking sheet with parchment paper.
Wipe the mushrooms clean and remove the stems. Use a small knife to carve simple skull faces into the caps.
Finely chop the mushroom stems and place them in a mixing bowl with the minced garlic, cream cheese, parmesan, salt, and pepper. Stir until the mixture is smooth.
Spoon the filling into each carved mushroom cap, pressing it down gently so it stays in place.
Arrange the mushrooms on the baking sheet and brush the tops with melted butter.
Bake for 18 to 20 minutes until the mushrooms are tender and the filling is lightly browned on top.
Sprinkle with chopped parsley before serving.