Preheat your oven to the temperature indicated on the croissant dough package, typically 350°F (175°C).
Open the croissant dough and separate it into 12 triangles. Cut each triangle in half lengthwise to make 24 smaller triangles.
Place a cocktail sausage at the wide end of each triangle and roll the dough tightly around it.
Brush each wrapped sausage with beaten egg and sprinkle with poppy seeds.
Arrange the piggies on a parchment-lined baking sheet, leaving space between them for even cooking.
Bake for 15–18 minutes, or until the dough is golden brown and cooked through.
Let cool slightly before serving with your favorite dipping sauces.