Chinese mythology
The Chinese dragon is one of the most important mythical creatures in Chinese mythology, considered to be the most powerful and divine creature and the controller of all waters who could create clouds with their breath. The dragon symbolized great power and was very supportive of heroes and gods. The conventional dragon has a certain description, however there are other dragons or dragon-like beings that vary from this description. For example, the Chi of mythology lacks horns. Dragons often chase or play with a mystical or flaming pearl. A dragon-fenghuang pairing is a common motif in art, the fenghuang often being called a "phoenix".
Longma
"Longma" or "dragon horse" connects with other creatures in Chinese folklore. While "longma" sometimes applies to the Qilin (Williams 1989:390), the closest relative is the legendary "tianma" 天馬 "heavenly horse" or the "Chinese Pegasus", which was metaphorically identified with the "hanxiema" 汗血馬 "blood-sweating horse" or Ferghana horse. A poem attributed to Emperor Wu of Han celebrates a 101 BCE victory over Western tribes.
The Heavenly Horses are coming, Coming from the Far West. They crossed the Flowing Sands, For the barbarians are conquered. … The Heavenly Horses are coming; Jupiter is in the Dragon. Should they choose to soar aloft, Who could keep pace with them? They will draw me up and carry me To the Holy Mountain of K'un-lun. The Heavenly Horses have come And the Dragon will follow in their wake. I shall reach the of Heaven, I shall see the Palace of God. (tr. Waley 1955:96-97) 
In Chinese astrology, the Dragon and Horse are two of the twelve animals. A "Zhuangzi" (列禦寇) story mentions finding a "pearl worth a thousand pieces of gold" under the chin of a "lilong" 驪龍 "black-horse dragon".