Headless Ghost(2007)

Original title: คนหิ้วหัว

Tei, a former sailor, is desperate for money. He reluctantly teams up with a group of thieves to rob a pawnshop to gain money for his daughter's school tuition, but the thieves betray him and brutally murder him by decapitation. Fortunately, Noom, a young and cunning thief discovers his head; it's still fresh, alive, even talking.