The yu (Chinese: 敔; pinyin: yǔ) was a wooden percussion instrument carved in the shape of a tiger with a serrated back comprising 27 "teeth," used since ancient times in China for Confucian court ritual music. It was played by striking its head three times with a bamboo whisk made from approximately 15 stalks of bamboo, and then scraping it across the serrated back once to mark the end of a piece of music.
The yu is mentioned, along with another percussion instrument called zhu (柷|), in pre-Qin Dynasty annals, and appears in the Classic of History.
The yu was adopted by the Korean court in ancient times, where it was known as eo (hangul: 어; hanja: 敔), and is still used in Confucian ritual music.