ALA Booklist (Tue Dec 01 00:00:00 CST 1992)

What if you had been kidnapped at birth and were the son of a king instead of a plain old kid? In this chapter book in the First Stepping Stone series, Marvin Redpost thinks that's just what's happened. It certainly seems coincidental that he's the only one in his family who has red hair and that the King of Shampoon's lost son happens to be a redhead. But Marvin's not entirely convinced he's a displaced person until his two best friends hop on the kidnapped-prince bandwagon. Soon, Marvin finds himself announcing his new status to his bemused parents and asking his mother to take him for blood tests to prove it. Not laugh-out-loud funny despite the tantalizing premise, but the situation will surely appeal to newer readers. Pencil sketches, scattered throughout, depict Marvin and his school buddies with just the right blend of mischief and humor. (Reviewed Dec. 1, 1992)

Horn Book (Wed Apr 01 00:00:00 CST 1992)

A funny, easy-to-read chapter book about a third-grade boy who is convinced that he was kidnapped at birth and is really the Lost Prince of Shampoon. The story is slight but may appeal to beginning independent readers.

Publishers Weekly (Fri Oct 06 00:00:00 CDT 2023)

This First Stepping Stone book (see preceding review) heralds the series debut of nine-year-old Marvin Redpost. He is convinced he is Prince Robert, the King of Shampoon's long-lost son currently being sought in a much-publicized campaign. First, Marvin is the only person in his family with red hair and blue eyes. Next, Marvin's teacher says that because he is left-handed he must have royal blood. And finally, Marvin does not remind his grandmother of anyone else in the family. All of this assures Marvin that he must have been kidnapped at birth and accidentally given to Mr. and Mrs. Redpost. Though the story line is frivolous, lively dialogue and Marvin's endless imagination command steady attention. Characterization, however scanty, is at least true to life, and the unresolved ending leaves readers something to think about. The rigid black-and-white illustrations, on the other hand, add little. Ages 6-9. (Aug.)