The very worst monster / Pat Hutchins.
Hazel sets out to prove that she, not her baby brother, is the worst monster anywhere. Since the Baby Monster arrived, no one notices big sister Hazel's talents. When Billy wins the Worst Monster Baby in the World contest, that's the final straw--Hazel must prove that she is the Worst Mons...
New York :
Walker Library - Curriculum Collection - Juvenile - 3rd Floor