Looking for kids’ fiction book between 1965-1976 that is about a quetzalcoatl. I remember that it was scary. I got it in my elementary school library so it was about 3rd-5th grade level. Children conjured up a quetzalcoatl by accident and it turned out to be evil and dangerous? Possibly turned an old feather boa into a quetzalcoatl using some magic dust they may have found in an old jewelry box.