What was Roald Dahl's first children's book?

Roald Dahl (13 September 1916 – 23 November 1990) was a British novelist, short story writer, poet, screenwriter, and fighter pilot. His books have sold more than 250 million copies worldwide.

The Gremlins is a children's book, written by Roald Dahl and published in 1943. It was Dahl's first children's book, and was written for Walt Disney Productions, as a promotional device for a feature-length animated film that was never made. With Dahl's assistance, a series of gremlin characters were developed, and while pre-production had begun, the film project was eventually abandoned, in part because the studio could not establish the precise rights of the "gremlin" story, and in part because the British Air Ministry was heavily involved in the production because Dahl, who was on leave from his wartime Washington posting, insisted on final approval of script and production.