Phaya Chalawan is a legendary giant crocodile from the folk tale "Kraithong," believed to reside in a mystical golden cave beneath Bueng Si Fai in Phichit Province. According to the legend, Phaya Chalawan possessed powerful magic and could transform into a human when inside the golden cave, where he required no food due to its sacred nature. The epic battle between Kraithong and Phaya Chalawan has become a vital cultural identity of Phichit, marked by a giant Phaya Chalawan statue at the entrance of Bueng Si Fai to welcome visitors to the city.