Near the beginning of the Rainy Season a little-known ritual is held in the outskirts of Chiang Mai. These are the Pu Sae and Ya Sae ceremonies which pre-date the introduction of Buddhism to Northern Thailand.
The traditions are associated with the Lawa, the earliest known inhabitants of Chiang Mai. According to tradition, Pu Sae and Ya Sae are considered the guardian spirits of Chiang Mai.
Pu Sae and Ya Sae were part of the indigenous inhabitants, the Lawa, of Northern Thailand before the establishment of the Mon Kingdom of Haripunjaya which would now be Lamphun. The Lawa were believed to have been head-hunters and cannibals, and this ties in with Pu Sae – Ya Sae ceremony that is still practiced today.
Legend has it that the while Buddha was traveling through the region he was being stalked by Pu Sae, Ya Sae and their son, with the intention of making him their next meal.
While meditating at Ban Panghai, Tambon Saluang, Mae Rim, Buddha became aware of his situation and stamped on a boulder which to still this day bears his footprint, and has become a shrine. This terrified trio forwent their previous intentions and instead sat and listened to a sermon. They were convinced to give up their way of life but they still hungered for human flesh.
The Pu Sae Ya Sae festival is held once a year it is a mix of the Thai Buddhism and the ancestral Lawa tradition. The Buffalo is brought to the area where he will be ceremonially slaughtered.
It is mix between Shamanism and Buddhism and you find monks attending this ceremony. The Shaman will go into a trans like state and become processed by the ancestral spirit of the Lawa people. In this state, he will eat the warm freshly killed meat of the water buffalo to appease the spirit and not to take the people of the village.