Thaman-Chah/θamá̃ ʤá

The Thaman-Chah is a mythical creature from Burma depicted in a watercolor painting from a Christian missionary. They are known to live in caves in the deepest forests. The story of their origin is that there were medicine men searching for a poisonous plant that could be used to create medicine. They found the plants but failed to say the proper mantras before collecting them, and were turned into tigers as punishment. Similar to this origin, it is sometimes believed that attempting to make a specific rejuvenating medicine (likely the same as the original) would cause a person to become a Thaman-Chah.

Citations:

Tantra, Magic, and Vernacular Religions in Monsoon Asia: Texts, Practices, and Practitioners from the Margins. United States, Taylor & Francis.