Black holes are formed from the collapse of extremely massive stars. While Neptune is a large planet, it's not massive enough to form a black hole.

It's important to note that:

* Planets don't form black holes. Black holes are the result of stellar evolution.

* Black holes exist at the centers of galaxies. While Neptune is part of our solar system, it's not located at the center of our galaxy (the Milky Way), where a supermassive black hole resides.

Let me know if you have any other questions!