What I loved: This is silly but fun, proposing all sorts of random things that may make up unicorns, such as ice cream for their manes and butterflies in their horns. The board book design is nice and sturdy, and the extra features, a pop-up at the end and a touchable mane on the cover add some fun.
What left me wanting more: The pop-up feature is cool, but if the book opens the whole way, it ends up being flat. The paper holding it on is also thin and easy for young children to tear (though thankfully there are multiple points of attachment). There are a lot of foods featured to make up unicorns, which are all sweets and some which toddlers (target audience) should probably not have like popcorn that gives some mixed feelings.
Final verdict: A silly and cute board book, WHAT ARE UNICORNS MADE OF? will appeal to unicorn fans who enjoy bright colors and rhyming text.