Yinglong () is a winged dragon and rain deity in ancient Chinese mythology.
This legendary creature's name combines yìng 應 "respond; correspond; answer; reply; agree; comply; consent; promise; adapt; apply" and lóng 龍 "Chinese dragon". Although the former character is also pronounced (with a different tone) yīng 應 "should; ought to; need to; proper; suitable", yinglong 應龍 definitively means "responsive dragon; responding dragon" and not "proper dragon".
The Chinese classics frequently mention yinglong 應龍 "a winged rain-dragon" in myths about the Three Sovereigns and Five Emperors, especially the Yellow Emperor and his alleged descendant King Yu. The examples below, limited to books with English translations, are roughly arranged in chronological order, although some heterogeneous texts have uncertain dates of composition.
Chu Ci
The (3rd–2nd centuries BCE) Chu Ci "Songs of Chu" mentions Yinglong helping King Yu 禹, the legendary founder of the Xia dynasty, to control the mythic Great Deluge. According to Chinese mythology, Emperor Yao 堯 assigned Yu's father Gun 鯀, who was supposedly a descendant of the Yellow Emperor, to control massive flooding, but he failed. Yao's successor, Emperor Shun 舜, had Gun executed and his body exposed, but when Gun's corpse did not decompose, it was cut open and Yu was born by parthenogenesis. Shun appointed Yu to control the floods, and after succeeding through diligently constructing canals, Yu divided ancient China into the Nine Provinces.
The Heavenly Questions section (3, 天問) asks about Yinglong, in context with Zhulong 燭龍 "Torch Dragon". Tianwen, which Hawkes 1985:38, 126) characterizes as "a shamanistic catechism consisting of questions about cosmological, astronomical, mythological and historical matters", and "is written in an archaic language to be found nowhere else in the Chu anthology" excepting "one or two short passages" in the Li Sao section.
When Lord Gun brought forth Yu from his belly, how was he transformed? Yu inherited the same tradition and carried on the work of his father.