Edgar Rice Burroughs

Edgar Rice Burroughs was the American author behind the John Carter and Tarzan books. Often in his works, he would employ the literary agent concept, where stories were presented as true accounts by the characters that the authors "came across" or discovered. As such, Disney decided to continue employing the idea in adaptations of his work.

The Legend of Tarzan
Edgar Rice Burroughs (referred to as Ed) appears in the clip-show episode Tarzan and the Mysterious Visitor. After the success of "A Princess of Mars", his publisher start wondering if he's got a new story in mind. Taking inspirations from a news article on the mysterious ape-man Tarzan, Burroughs begins researching Tarzan and eventually makes his way to Tarzan's jungle and getting a proper insight into Tarzan and Jane from the people themselves.

John Carter
Following the preface of the original "A Princess of Mars" story, a young Edgar Rice Burroughs is invited to his uncle John Carter's mansion to collect his inheritance in light of his supposed death. He is put in charge of the estate and is the sole person that is allowed to look at his diary, which contains the story of how Carter found his way to Barsoom. As the story wraps up, we discover that John faked his death, using his "death" and his nephew's arrival to bait the Therns that were on his trail. After killing the Thern, retrieving a medallion and planning on returning to Barsoom, Carter instructs him to stay in the Mansion and make sure the "tomb" containing his Earth body stays undisturbed while he returns to his new home. He also suggests to Edgar to "take up a cause or write a book".

Trivia
Edgar Rice Burroughs' appearance in The Legend of Tarzan, as well as his role in the episode he appeared in, are very similar to what happened in the Little Mermaid episode "Metal Fish". On both occasions, the main protagonist meets a mystery character who turns out to be the author of their respective books. In Ariel's case, it was Hans Christian Andersen.