Mythology is a miscellaneous collection of old tales and legends which embraces all of what we now call religion, science and philosophy (natural moral and metaphysical). The Myths are the spiritual instructions of our forefathers. The mythical stories are not entertainment stories or folktales; because they can be told only at certain times of the year and under certain conditions. The belief systems of all the 14 (fourteen) mountain tribes and races of Sikkim were sandwiched between the faith of Buddhism from the north and Hinduism from the west in the beginning; and then Christianity from the south mainly during the chiefdom periods of Sikkim (16421975 A.D.) and Nepal (17692008 A.D.); affecting their indigenous belief systems tremendously. Today, the different tribes and races of Sikkim have awakened not against anybody else but themselves from within and have started rediscovering their own belief systems and traditions. Many of these hill tribes or races have adopted many well developed religions of the world with insignificant traces of their own within it. This book is an attempt to collect the valuable information of these lesser known oriental “Belief System” or “Religion” and “Mythologies” of the different ethnic mountain people of Sikkim for the first time for further research and development.