Preheat your oven to 350°F (175°C).
In a large mixing bowl, combine the softened cream cheese, sour cream, mayonnaise, lemon juice, Worcestershire sauce, garlic powder, and onion powder. Mix until smooth and well blended.
Gently fold in the chopped shrimp, lump crab meat, shredded cheddar cheese, and green onions. Season with salt and pepper to taste.
Transfer the mixture to a baking dish and spread it evenly.
Bake in the preheated oven for 25-30 minutes, or until the dip is bubbly and golden on top.
Remove from the oven and let it cool slightly before serving.