The appearance of the Sin-you is similar to that of a Qilin, but more feral and imposing. It is a large quadruped with a feline or ovine body, a shaggy mane, and is either depicted with hooves or feline paws (the latter often to stress its difference from the Qilin). In has a single, unbranching horn in the center of its head, like a western unicorn. The Sin-you’s eyes are said to be very intense and imposing, figuratively burning into whomever it gazes at in a predatory fashion.
The Sin-you is highly symbolic of justice, and is believed to have the power to know if a person is lying or know if they are guilty with a glance. It sometimes depicted at court beside the ruler or judge: if a person told a falsehood in its presence, it would leap forward and impale the perjurer though the heart with its horn. In other instances, the judge would put convicted murderers before the Sin-you, who would slay them in the same fashion if they were truly the perpetrator, but leave the innocent unharmed.
- Rose, Carol M. (2001). Giants, Monsters, and Dragons: An Encyclopedia of Folklore, Legend, and Myth. New York: W.W. Norton & Company. p. 377. ISBN 0-393-32211-4.
- South, Malcolm (1987). Mythical and fabulous creatures: a source book and research guide. Westport, Conn: Greenwood Press. p. 16. ISBN 0-313-24338-7.
- Leeming, David Adams (1997). Storytelling Encyclopedia: Historical, Cultural, and Multiethnic Approaches to Oral Traditions Around the World. Phoenix, Ariz: Oryx Press. p. 474. ISBN 1-57356-025-1.
- Gould, Charles (2009). Mythical Monsters. BiblioLife. pp. 357–359. ISBN 0-559-10836-2.
- Conway, D. J. (2001). Magickal Mystical Creatures: Invite Their Powers Into Your Life. Saint Paul: Llewellyn Publications. p. 25. ISBN 1-56718-149-X.