Themes: Land Monsters, Nonfiction, Tween. Do eyewitness stories and grainy photographs prove the existence of monsters like Bigfoot or Yeti, or do people see what they want to see? Red Rhino Books Nonfiction is the first Hi-Lo children's nonfiction series at a first-grade reading level for students in grades 4–7. Visually appealing fullcolor photographs and illustrations—along with fun fact boxes—keep these books flowing. Also includes prereading comprehension questions along with a 20-word glossary for further reading support.