Dragons

"What, or, uh, who is Shou-Lao?" "A dragon." "Okay. Wow. Dragons aren't real." "Why would you think that?"

- Claire Temple and Davos

The Dragons are an ancient race of mystical creatures that possess an incredible amount of Chi. Their bones are the primary ingredient of the Steel Serpent drug and of the Resurrection Elixir, a regenerative substance granting immortality and created by the five founders of the Hand.

History
"These creatures once roamed the green valleys of my home."

- Madame Gao

Dragons once lived in K'un-Lun, with the ability to fly and live freely. Over the years, Shou-Lao remained the only dragon living in the city, using his abilities to provide the one who defeats him the power of the Iron Fist.

Ever since they were banished from K'un-Lun, the five leaders of the Hand excavated holes across the Earth where the dead dragon bones were buried in order to use them for their Elixir. For centuries, their Modus operandi caused the destruction of several cities, and they were believed to have caused the destruction of Pompeii in 79 AD and the Chernobyl disaster in 1986.

At some point before the 21st century, the Hand discovered a new dragon skeleton under the foundations of New York City, but an Iron Fist sealed the remains with his powers and prevented the collapse of the city. Only accessible by an individual gifted with the Iron Fist, the Hand intended to manipulate Danny Rand to unlock the bones, but they were stopped by the Defenders.

Trivia

 * In the comics, the Dragons of K'un-Lun are one of the many different species of dragons that exists in the universe.