Moon

The Moon is as you guessed, our own Moon. For some reason it is sentient with a very realistic human face on it.

It likes to give Mike advice during night time. The Moon considers Mike "his only friend". Mike doesn't seem to care that the planets very own Moon has a human face and is talking to him.

The Moon however is one of the most friendly people around. Sometimes he can be seen as "Too Kind" as he accidentally helped the RUC by giving them directions.

Despite is overly friendliness, The Moon is extremely wise due to his length in Space.