The Metamorphoses of Apuleius, better known as The Golden Ass (Latin: Asinus aureus) is the only complete surviving Latin novel from antiquity. In eleven books, it tells the story of Lucius, a Greek who is magically transformed into an ass, undergoing in that form a series of picaresque adventures.
Free online texts
The English Server: The Golden Asse, English translation by William Adlington (1566). HTML format. Archived at the Internet Archive.
Forum Romanum: Metamorphoses. Latin text. HTML format. (Book I missing as of Dec 2018).
Gutenberg: The Golden Asse, English translation by William Adlington (1566). Multiple formats.
Internet Archive: The Golden Ass, Greek text and English translation by William Adlington, revised by S. Gaselee (1924). Loeb edition. Multiple formats.
Perseus: Metamorphoses. Latin text. HTML and XML formats.
Poetry in Translation: The Golden Ass, translated by A.S. Kline (2013). Multiple formats.
University of Adelaide (Internet Archive): The Golden Asse, English translation by William Adlington (1566). Multiple formats.
Conceptual Fiction: The Golden Ass, by Ted Gioia. Interprets the work as a precursor of magical realism.
Librivox: Metamorphosis or The Golden Ass. Public domain audiobook.
Literature and History: Episode 73 - The Golden Ass, podcast by Doug Metzger.
Miami University/Internet Archive: Book One and Apuleius' Metamorphoses, by Stephen A. Nimis.
The Golden Ass, by Benjamin Slade.
The Great Conversation: Further reading at Tom's Learning Notes
Lucian: The Ass - may be a version of the Greek original which Apuleius adapted for his story.
Latin Resources: Online materials for learning Latin.
Bloom's Western Canon: The Golden Ass is listed.