The Qilin is a mythical hooved Chinese chimerical

Chimera (mythology)

The Chimera or Chimaera was, according to Greek mythology, a monstrous fire-breathing female creature of Lycia in Asia Minor, composed of the parts of multiple animals: upon the body of a lioness with a tail that ended in a snake's head, the head of a goat arose on her back at the center of her...

 creature known throughout various East Asia

East Asia

East Asia or Eastern Asia is a subregion of Asia that can be defined in either geographical or cultural terms...

n cultures, and is said to appear with the imminent arrival or passing of a wise sage

Wise old man

The wise old man is an archetype as described by Carl Jung, as well as a classic literary figure, and may be seen as a stock character...

 or an illustrious ruler. It is a good omen that brings rui . It is often depicted with what looks like fire all over its body. It is sometimes misleadingly called the "Chinese unicorn

Unicorn

The unicorn is a legendary animal from European folklore that resembles a white horse with a large, pointed, spiraling horn projecting from its forehead, and sometimes a goat's beard...

" due to conflation

Conflation

Conflation occurs when the identities of two or more individuals, concepts, or places, sharing some characteristics of one another, become confused until there seems to be only a single identity — the differences appear to become lost...

 with the unicorn by Westerners.
The earliest references to the Qilin are in the 5th century BC book Zuo Zhuan

Zuo Zhuan

The Zuo Zhuan , sometimes translated as the Chronicle of Zuo or the Commentary of Zuo, is among the earliest Chinese works of narrative history and covers the period from 722 BCE to 468 BCE. It is one of the most important sources for understanding the history of the Spring and Autumn Period...

.