The Black Moon was a planet during "Weegee's Time Machine"
The black moon was not a Moon at the time it was a planet the size of Earth and it was called
back then Vezon.It was conquered by Weegee he than slayed everybody on it in the blink of an eye with dark magic he got from defeating Dimentio. He then shurnk it to 1/4 of its size and put black energy on it. Later on the Cheese Haters made a fortress on it to produce Oyxgen to replace Nitroglycerin which was the replacement of Oxygen.
Unlike it's name it really has lakes and trees due to it being a former planet.