Changyou is a mythical ape‑like creature in ancient Chinese mythology, resembling a monkey but with four ears. Its cry sounds like a human groan, and it is regarded as a harbinger of catastrophic floods.

A wild beast known as Changyou once roamed the mountains of Changyou.

The mountain itself was named after this creature; Changyou’s appearance closely resembled that of a monkey, yet it sported four ears—and its vocalizations echoed like the moans of a human in distress.

The emergence of Changyou was seen as a clear sign of impending flood disaster. According to legend, some travelers had once spotted Changyou in the mountains and heard its mournful cries—only to witness a once‑in‑a‑century mega‑flood strike the region shortly thereafter. The following year, when Changyou reappeared, an even more devastating flood struck—leading people to regard it as a reliable omen of waterborne calamity.