The Serpent's Shadow by Rick Riordan

The Serpent's shadow is the last book in the Kane Chronicles series. It tells of the many perils the two magicians face in modern times, battling the evil of Egyptian Mythology. The giant serpent eats the sun in the story, thus creating doomsday. The only thing that can stop him is the destruction of his shadow. After the ice cream man died, the serpent put himself inside a giant chicken. Carter and Sadie, the two magicians must find his shadow and destroy it, before chaos wins. -AbdurRahman