A troubled little unicorn needs serious help. There are "worry gremlins" all around threatening his peace of mind. Kids will feel engaged and empowered as they follow the directions to get these gremlins out of the picture. Young readers are told to "wiggle your fingers to make some magic dust," tickle the unicorn, tell him a joke, and shake the book. None of these tactics quite do the trick, since the gremlins keep coming back and Unicorn's horn gets stuck in the page. A gentler shake frees the horn, and the text offers another solution, one that kids can take to heart--"The best way to get rid of a worry is to tell someone about it." Luckily, Unicorn's friend Monster, an innocuous blue being with tiny pink horns, is there for Unicorn to whisper his worries to. Readers are also urged to whisper something encouraging to Unicorn, who thereafter feels much better. Fears allayed, he and his friends indulge in an exuberant celebration. Kids can join in as they happily sing together against a double-page spread of stars, rays of light, fairies, and disappearing gremlins. The digital illustrations are humorous, and varying typefaces and energetic page reveals add to the fun. This entry in the Who's in Your Book? series follows the same pattern as the others and includes characters from the previous books. A simple but important lesson about anxiety that will speak to young worrywarts everywhere. (Picture book. 3-5) Copyright (c) Kirkus Reviews, used with permission.