Preheat oven to 350 degrees F (175 degrees C).
Combine cream cheese and mayonnaise in a large bowl until smooth; stir in garlic.
Gently stir artichoke hearts, crab, Parmesan cheese, ⅓ cup green onion, ⅓ cup red bell pepper, and cayenne pepper into cream cheese mixture.
Transfer the dip to a 9-inch pie dish and sprinkle top with bread crumbs.
Bake in the preheated oven until crumb topping is golden brown and dip is hot, 20 to 30 minutes.
Garnish with 2 teaspoons green onion and 2 teaspoons chopped red bell pepper.
