This research attempts to disclose the features and composition of an ancient manuscript which dates back more than one and a half millennia. The book of Fisəlgos is not an indigenous work of the Ethiopian Church scholars, but a 5 Abstract th The book has the nature of a bestiary or animal lore according to ancient natural Philosophy. It also shows a Christian knowledge of the Holy Bible. It talks about fantastic creatures like animals, birds, and even plants and precious stones. The book has philological, dogmatic, and moral value: Philological, for it dates more than one and a half millennia, holds much historical as well as scientific knowledge of nature and could be studied in variant readings; dogmatic, for it correlates the natures of creatures with the person of Christ and His salvific works and teaches about the Godhead; moral, because it holds ethical thoughts instructing believers to "reason from nature". century translation of a book called Physiologus which was originally composed in Greek in Alexandria in about 140 AD. Though the writer remains anonymous, there is a hypothesis that it was translated into Gə’əz in about the fourth to fifth century by Aba Selama Kesate Berhan or by the nine Saints or by a bilingual Ethiopian scholar who remains unidentified. The research shows that the book of Fisəlgos has a lot to do with the Ethiopic andəmta which has nurtured the religious thoughts and moral philosophy of the Ethiopian Orthodox Tewahido Church. The book of Fisəlgos discloses much knowledge in the fields of natural history, philosophy and language as well. Thus the thesis recommends further study of variant readings and a critical edition.