The global cinematic zombie genre has led to interactions with diverse cultures, resulting in diverse context-dependent adaptations. Similarly, the introduction of zombies as new monsters into cultural environments where they were hitherto unknown has enabled horror cinema to explore issues or themes beyond those conventionally associated with the culture’s indigenous monsters. In the Thai context, horror cinema predominantly consists of ghost films where Buddhism carries significantly thematic weight. The incorporation of zombies—creatures inherent with religiously subversive power—into this context has led to some forms of fusion with local ghosts and encounters with Thai Buddhism. In contrast to Thai ghosts, whose existence upholds and validates Buddhist principals, zombies undermine them, rendering them useless or insignificant. Examined in this chapter are two Thai zombie films, E-san of the Dead (2022) and E-sarn Zombies (2023). Both fuse zombies with phi pop, a ravenous folkloric spirit, a fusion that relies on the shared characteristics between the two creatures. The zombies then challenge some key Buddhist principles, a challenge that becomes a means for Thai horror cinema to go beyond the conventional role of doctrinal validation associated with Thai ghosts.