Skellig by David Almond

This story is about an 11-year-old boy named Michael who moves into this old house that seems to be falling apart. His new baby sister is sickly with a heart condition and may not live long. After the family moves in, Michael goes to the backyard to explore the broken-down garage and in the piles of boxes and forgotten junk, he meets an old and strange man going by the name Skellig. As Michael and his new neighbor friend, Mina, get to know the man better, they discover that the man has arthritis, likes the Chinese food menu order numbers 27 and 53 with brown ale...and that he has wings...