What is the pen name of the pony who writes the Daring Do books?

The pen name of the pony who writes the Daring Do books is A.K. Yearling.

The name is introduced as the byline on Rainbow Dash’s favorite adventure novels. In the fourth-season episode “Daring Don’t,” Rainbow Dash and her friends track down the reclusive author after a book is delayed. They discover that A.K. Yearling is actually Daring Do herself, the pegasus whose exploits fill the novels.

That revelation changes the books from fictional adventure stories into dramatized accounts of Daring Do’s real encounters with figures such as Ahuizotl and Dr. Caballeron. Daring uses the author identity to protect her privacy while publishing her adventures. The name is also a playful reference to J.K. Rowling, author of the Harry Potter series, while “yearling” is a term for a young horse.

A common mix-up is treating Daring Do as merely the fictional hero and A.K. Yearling as a separate writer. In the show’s story, they are the same pony, making A.K. Yearling the canonical answer.