Eponymous author

The eponymous author of a literary work, often a work that is meant to be prophetic or homiletic, is not really the author. An anonymous author chooses to write in the name of another. This eponymous author is not merely a pen name for the real author, but someone with a completely different identity. The author is often

* a real person who is famous, but usually long deceased, whom the author has chosen to achieve recognition or fame for his work. Such a work is said to be pseudepigraphical. For example, Jeremiah was said to be the author of Lamentations, and Solomon the author of Song of Songs. Most biblical scholars attribute both works to later authors, writing eponymously.
* a fictitious person, cloaking the identity of the real author. The fictitious author is often clearly not a real person. The character of the fictitious author, as perceived by the reader, may itself be a fictional device.
* a fictitious person, even though the identity of the real author is well known. John Updike created an interview of himself, conducted by Henry Bech, one of his fictitious characters.

Sources

* Sandys-Wunsch, John. "What Have They Done to the Bible: A History of Modern Biblical Interpretation". Liturgical Press (2005).