Kalatra
The Kalatra were a race encountered by the Thirteenth Doctor in Hong Kong, 1972.
History
The Kalatra were once a warrior race, who eventually took control of their home world. However, they decided to stop waging war, and instead sent out their warriors throughout space as embryos. Those which survived and grew up were then given the opportunity to take control of their host worlds. In order to succeed, they had to beat the champion of their host world in a fight.
In 1940, Chen Luo found one of the ships carrying an embryo in Guangli Bay, off Hong Kong, whilst fishing. He raised the Kalatra warrior as his son, calling him Shui Long. In 1972, the Kalatra arrived to give Shui Long the chance to take over planet Earth. However, he was bested in the fight by martial arts expert Bruce Lee, and so did not gain control of the planet. (COMIC: The White Dragon)