The first mention of “Giant” for Thai people is in the literature textbook “Ramakien”. The Demon King Ravana performs in an unjust side, and fights with a fair side of Rama and Lakshmanan. Until people know the word “Giant” is a bad guy.
For deeply research in more detail, Giant is divided into White & Black side. Therefore the image of Giant features the fearfulness and bravery but it cannot decide to the real mind of each giant and considers at their role and performance.
Besides the giant in the textbook, Thai people also believed in giant being a guardian for goodness and getting rid of evil spirits since Ayutthaya period, which led to the establishment of the Guardian Giant at the entrance of the temple.
There are six pairs of demon guardian statutes at the entrance gates to the Wat Phra Sri Ratana Sasadaram (Temple of the Emerald Buddha). These are the main Giants of the Ramakien. They stand facing the ordination hall (Phra Ubosoth) meaning that they are guarding the Emerald Buddha inside from all evil spirits.
These demon guardians were built in the reign of king Rama III, each one describing an important character in the Ramakiean story. The green one describes Tosakanth, the demon King and red one represents Sahassadeja, one of Tosakanth's warriors.