Preheat the oven to 375°F.
In a large mixing bowl, combine the lump crab meat, cream cheese, shredded cheddar cheese, green onions, Worcestershire sauce, garlic powder, Old Bay seasoning, and black pepper. Gently mix until well combined.
Using your hands, form the mixture into small balls, about 1 to 1.5 inches in diameter.
Place the panko breadcrumbs in a shallow dish and roll each crab ball in the breadcrumbs until fully coated.
Arrange the crab bombs on a baking sheet lined with parchment paper and drizzle or spray with cooking oil.
Bake in the preheated oven for 20-25 minutes, or until golden brown and heated through.
While the crab bombs are baking, mix the mayonnaise and lemon juice in a small bowl to create a dipping sauce.
Serve the crab bombs hot with the dipping sauce on the side.