Shenron was the wish granting dragon created by Kami and the Dragonballs. After Kami died, Dende recreated the dragon, and he was then able to grant two wishes per summon.
Shenron/Shenlong is named after the spiritual dragon of the same name in Chinese mythology, who is known as the master of storms and a bringer of rain (to the point of being a weather entity). Shenlong is often shown with azure/green-colored scales and is said to be five-clawed (marking its stats as an imperial dragon).
It is a common tale that those in old days of China would appease a Shenlong to pray for plentiful rainfalls. However, akin to both the symbolism of rulers and dragons alike it is easy to enrage one with a poor gift or in a more common way (ruffling their scales via the "nilin/gekirin" concept). In the Shenlong's case, how they vent their said rage is often through creating destructive rainstorms and hurricanes.
In Dragon Ball, the Shenlong here is often referred to in its pinyin/Mandarin reading (pronounced as "Sheh-n-loh-ng" or "Sheh-n-roh-n", but pronounced as "Sheh-n-rah-n" in the Funimation dub as a mispronunciation). In the Japanese on'yomi reading used for names like Goku's and his family, as well the Ox King, Shenron and Shenlong's names alike are to be said as "Shinryū" (this on'yomi pronunciation is not used in the series).
- In Dragon Ball GT. it it revealed because of the Black Star Dragon Balls, Shenron has a polar opposite named "Black Smoke Shenron" whom the 7 Shadow Dragons are collectively part of.