Preheat oven to 375°F. Flatten biscuits slightly on a baking sheet.
Combine shrimp, crab, mozzarella, cream cheese, Old Bay, and parsley.
Spoon filling onto half of biscuits; top with the rest and pinch edges.
Coat tops with melted butter.
Bake for 13–15 minutes until golden.
Let rest for 2 minutes before serving.
