Preheat the oven to 375°F (190°C).
In a mixing bowl, combine the cream cheese, shredded crab meat, cheddar cheese, green onions, garlic powder, Old Bay seasoning, and black pepper. Mix until well combined.
Unroll the crescent roll dough and separate it into triangles on a baking sheet lined with parchment paper.
Place a generous tablespoon of the crab mixture at the wide end of each crescent triangle.
Roll the dough from the wide end to the point, enclosing the filling, and place seam-side down on the baking sheet.
Brush the tops of the crescent rolls with the beaten egg for a golden finish.
Bake in the preheated oven for 12-15 minutes or until golden brown.
Remove from the oven and let cool for a few minutes before serving.