Preheat oven to 375°F (190°C).
In a large bowl, mix together cream cheese, sour cream, mayo, mustard, lemon juice, Worcestershire, and Old Bay until smooth.
Stir in the shredded cheddar cheese.
Gently fold in the lump crab meat, keeping the pieces intact.
Transfer to a small oven-safe baking dish (9-inch) or pie dish.
Sprinkle the rest of the shredded cheddar and sprinkle Old Bay on top for a golden crust.
Bake for 25–30 minutes, until hot and bubbling.
Garnish with green onions or parsley if desired.