King Og of Bashan has written down his life experiences, and they appear on Chabad.org!
I have lived a long life, and it is difficult to remember all that I have experienced. I am forever indebted to the Jewish people for being so diligent in their note-taking and for making sure that history is not forgotten. My story can be pieced together from accounts recorded in their texts, both in the written Torah, as well as in the collection of teachings known as the Midrash.
You can have a read of Og’s memoirs here. It seems that Chabad.org staff writer Shaul Wolf has helped him compile his memoirs from Genesis, Numbers, Deuteronomy, Genesis Rabbah, Targums Jonathan and Onkelos, the Talmud, Pirke De-Rabbi Eliezer, Nahmanides (Ramban), Samuel ben Meir (Rashbam), Maimonides (Rambam), Abraham ibn Ezra, Shlomo Yitzchaki (Rashi), Daat Zekeinim and Baal HaTurim.