Bel and the Dragon
The narrative of Bel and the Dragon is incorporated as chapter 14 of the extended Book of Daniel. The original Septuagint text in Greek survives in a single manuscript, Codex Chisianus, while the standard text is due to Theodotion, the 2nd-century AD revisor.
This chapter, along with chapter 13, is considered deuterocanonical: it was unknown to early Rabbinic Judaism, and while it is considered non-canonical by most Protestants, It is included in Catholic, Eastern Orthodox, Oriental Orthodox, and Assyrian Church of the East bibles, and is found in the Apocrypha section of some Protestant Bibles.
"Perhaps composed as early as the Persian period (539–333 BCE)".