Mujo is generally used nickname (in Bosnia and Herzegovina as well as in other countries of ex Yugoslavia region) for someone whose name is Mustafa (eng. Mustapha). This nickname is commonly used as name of main character in urban jokes. It has also been used by Serbian propaganda to represent Muslims of the region as stupid , bad mannered, impolite etc.
Mujo is walking down the street carrying scissors. His friend sees him and asks why you are carrying scissors. Mujo replies I had a call from the E.R. (emergency room) they told me that my mother in law’s life is hanging by a thread.