In The Kite Runner by Khaled Hosseini, what do the neighborhood children call Ali? What does it mean, and why do they call him this?

In The Kite Runner (Hosseini), we learn fairly early in the book of the divide between Pashtun Sunnis and Hazara Shi'a in Afghanistan: the former is the ruling class and the latter is a far lower class.  Ali and Hassan are Hazara Shi'a and the servants of Baba and Amir, who are Pashtun Sunnis.  The neighborhood children, led by Assef, who is the bully of the neighborhood, call Ali "Babalu" (38). This means...

In The Kite Runner (Hosseini), we learn fairly early in the book of the divide between Pashtun Sunnis and Hazara Shi'a in Afghanistan: the former is the ruling class and the latter is a far lower class.  Ali and Hassan are Hazara Shi'a and the servants of Baba and Amir, who are Pashtun Sunnis.  The neighborhood children, led by Assef, who is the bully of the neighborhood, call Ali "Babalu" (38). This means "Boogeyman."  Just in case that is a word you are not familiar with, a boogeyman is an imaginary monster, the sort of monster you picture waiting for you under your bed or in your closet when you are a small child.  Assef taunts Ali relentlessly.  He says "Hey, Babalu, who did you eat today?" (39) and calls him a "flat-nosed Babalu" (38) and a "slant-eyed donkey" (38). Ali had had polio as a child, so he dragged his affected leg, and the references to his nose and eyes are no doubt because the Hazara are more Asiatic in appearance than the Pashtun, with different ethnic origins.