Billina is a character from the book "Ozma of Oz," written by L. Frank Baum. She is a talking hen who accompanies Dorothy on her adventures in the magical land of Oz. Billina is known for her cleverness and bravery, often using her quick thinking to help her friends. In the story, Billina plays a crucial role in assisting Dorothy and their companions, including Toto and the Cowardly Lion. Her ability to speak and her unique perspective make her an important ally in overcoming challenges they face in their quest.