The mythical creature commonly placed on rooftops to protect against fire is Chiwen.
Chiwen is both a fish-like Chinese dragon and a roof ornament used on traditional Chinese architecture. Usually installed at the ends of a roof ridge, the creature’s wide mouth and curled body were understood symbolically as swallowing evil influences and guarding the structure. Its association with water also made it a fitting supernatural defense against fire in buildings that were often made largely of wood.
The tradition has deep architectural roots. Early forms called chiwei appeared in Han-dynasty art and architectural models. During later periods, especially the Tang and Song dynasties, fish- and dragon-shaped ridge ornaments became increasingly standardized. The technical treatise Yingzao Fashi, compiled in the Song dynasty, described formal construction details and measurements for such roof decorations.
Chiwen is commonly counted among the nine sons of the dragon, although lists and rankings vary across sources. It should not be confused with Pixiu, a wealth-associated creature, Taotie, a motif known for its insatiable appetite, or Bixi, the tortoise-like dragon son associated with carrying monuments. In some feng shui traditions, Chiwen is also linked with protection from floods and typhoons.