I assume this is a cultural thing that I am not aware of, but a friend just updated their status to say:
Xīwàng māo jiù biàn chéng tiānshǐ shǒuhù quán jiā
Who or what is 猫舅?
猫舅 in this sentence just means cat. It's become slang to say 猫舅 when one just means cat.
Also the following might be helpful too:
My guess is:
Your friend might have some dogs, cats and other animals as pets. He might want to regard all these pets as a big family, to each member of which he might want to give a lovely nickname. For example, he might have:
I don't know the word "猫舅".
舅舅 is used to refers to a brother of your mother. If one's mother is A, and she has two brothers: B and C,
So I guess 猫舅 is used to call a brother of the cat's mother. In your example, you friend uses this word from a cat's view.