Good answers. My Strong’s Exhaustive Concordance lists over 20 entries for him.
I’m reading the massive “Outside of Scripture” (OOS) published by the Jewish Publication Society. Under the heading of “Septuagint”, the book discusses the apocryphal 1 Esdras (Ezra).
In it, Zerubbabel is credited with a role somewhat parallel to Esther’s role in the Book of (what else?) Esther.
Zerubbabel is a personal guard of the Babylonian king, and he wins a contest for which the prize he claims is the release of the Jews from Babylon. His role described in 1 Esdras fills in a gap in Ezra-Nehemiah telling how the return from captivity came about. The overarching point of view is that all this occurred not only as Jeremiah foretold, but specifically in accordance with Providence.
The relationship between the Septuagint and the Masoretic text is complex. The goal of OOS is to document Jewish belief and practices of the second Temple era that are not so documented in what later became the official Hebrew scripture.