Preheat your oven to 375°F (190°C). If using parchment paper, line a baking sheet with it.
In a mixing bowl, combine the chopped shrimp, crab meat, cream cheese, green onions, garlic powder, Old Bay seasoning, and black pepper. Mix well until all ingredients are fully incorporated.
Open the crescent roll dough and separate it into triangles along the perforated lines.
Take a heaping tablespoon of the shrimp and crab mixture and place it at the wider end of each triangle.
Roll the dough around the filling, starting from the wide end and working your way to the tip. Pinch the ends to seal the filling inside, ensuring there are no gaps.
Place the stuffed crescents on the prepared baking sheet, spacing them out evenly.
Brush the tops with the beaten egg to achieve a golden-brown finish.
Bake in the preheated oven for 12 to 15 minutes, or until they are golden brown.
Once baked, remove from the oven and allow to cool for a few minutes before serving.