Origin of ancient Indian toxicology can be dated back to vedic literature. Toxins of both animate and inanimate world were very well understood during the era. Rig and Atharva vedic texts describe such details. After classifying such toxins, Charaka Samhitha, thebasic literature of Indian Medicine used gold and ghee as panaceas to counter act them. Ayurveda considers toxicology as one among the eight specialized branches of medical wisdom. Unfortunately, the available literature on this is very limited. Moreover, they have been discussed briefly in Charaka and Sushrutha Samhitha. Mangarasa I, a Jain scholar who lived on the foothills of the Western Ghats, in Southern India in 1350 A.D., felt this vacuum and composed an independent, elaborate Kannada text on toxicology. His less known text Khagendra Mani Darpana (KMD) is the first ever documented complete text on toxicology in the world. Medieval Indian wisdom on plant and animal diversities are very well reflected in this unique toxicological text. Centuries past to Linnean era, KMD gives vivid descriptions on zoological and botanical diversities of the time. This astonishing fact is an evidence of our ancestor's curiosities about the nature around them. A critical overview of the bio-diversity described in KMD text is discussed in this paper.