Venom's moon

Venom has a very small one moon that orbits around it. It is a very small dwarf planet or asteroid that has been converted into a giant teleportation device.

In Nintendo World, Venom has a much smaller moon, and when Fox and General Pepper go through a portal there, it's revealed to have been modified into a moon-sized teleportation device, with large portions of the moon having machinery built directly into its surface and interior. A single large teleporter on the moon provides a path into the mysterious Corridor of Illusions, which itself leads to Andross's secret lair.

After been exiled to Venom, Andross was able to build a teleporter of his own into Venom's moon, allowing him to remotely deploy his forces anywhere and even warp the entire moon out of normal space-time as he saw fit.

The alternate medium route on Venom is accessed by flying a tunnel where a wormhole was opened by Andross to access Venom's moon. With the help of General Pepper, it would be here where Fox would fight Star Wolf on their Hunters, and then come face to face with Andross.