Muley is a crazy old guy. In the book, he is a big friend of the Joad family. These two families had the same desire – to leave.
Once he lost his house, land, and everything he liked. After that lost his wife and their children decided to run away and begin living from the beginning in California, but unfortunately Muley refused to go, saying that his only home is in California. In one of the episodes, he attempts to elude the police (who could arrest him for trespassing) and to live outside of society.
You know, it seems to us that here he appeared like a very proud person. However new landowners are very cruel and Muley needs to hide every time. After his family goes away, he sleeps in different places, becoming a transient, sleeping in abandoned houses or secret places hidden near the river or in the fields. Now his life has changed. He creates mischief and tries his best to make the landowners' lives difficult. He wonders if he is going crazy. Can we judge him for refusing to go with his family to the new place? We can’t live in reality, because no place can replace the homeland.
Muley Graves in the Essays