ขุนช้างขุนแผน ตอนปราบจรเข้เถรขวาด is a 1982 Thai film directed by Sompote Sangduenchai and starring Sombat Methanee, Sor Asanajinda, Toon Hiransap, Naowarat Yooktanun and Duangcheewan Komolsen.
During Ayutthaya period, a middle age man, Master Taen (อาจารย์เถร), has strong magic knowledge (วิชา) so can seduce women through spells and can transform himself into a ferocious crocodile. His young apprentice (ลูกศิษย์) can also become a fierce crocodile. Young ladies Simala and Soifa are the wives of noble Phra Phi but Phra Phi spends all nights with Simala. Soifa becomes very jaleous and asks Master Taen to help her. Master Taen uses black magic incantations. Simala and Phra Phi get tortured like voodoo puppets. Due to incantations (พิธี), Simala gets a defigured face so that Phra Phi goes back to Soifa. Phra Chumpoon, Phra Phi's brother, tries to defend Simila. Soifa asks Master Taen for a love filter to force Simala having an affair with Phra Chumpoon so that she can be repudiated by Phra Phi. Nothing happens but Phra Phi nevertheless chases her. Phra Chumpoon asks for his father's help. The father, Paen, sees that his son is under spell influence. Soifa starts to panic. The king orders to arrest Master Taen but Master Taen and his apprentice become crocodiles to kill the soldiers. A reward is offered to catch the crocodiles. Paen searches for evidence such as wax effigy inside the bedroom. Soifa starts to panic. The king orders to arrest Master Taen but Master Taen and his apprentice become crocodiles to kill the soldiers. A reward is offered to catch the crocodiles. Paen searches for evidence such as wax effigy inside the bedroom. But nothing found as Soifa hides it well but Paen succeeds to find it and breaks the spell (พิธีแก้) for Simala. Master Taen sends an evil spirit to fight Paen but Paen's baby spirit (กุมารทอง) helps him. Master Taen is arrested by Phra Chumpoon. He refuses to break the spell for Phra Pi. Simala and Soifa need to show their purity (บริสุทธิ์) by walking without pain on hot charcoal. Soifa fails (ความดีต้องชนะความชั่ว) and is chased in Northern Thailand. The two crocodiles continue their rampage until they are stopped by Paen and Phra Chumpoon. Master Taen is defeated and killed by Phra Chumpoon.