The term “Panda Blood” is being used in China to describe rh negative blood.
Pandas are very rare:
The panda is a conservation reliant endangered species. A 2007 report shows 239 pandas living in captivity inside China and another 27 outside the country. Wild population estimates vary; one estimate shows that there are about 1,590 individuals living in the wild, while a 2006 study via DNA analysis estimated that this figure could be as high as 2,000 to 3,000. Some reports also show that the number of pandas in the wild is on the rise. However, the IUCN does not believe there is enough certainty yet to reclassify the species from Endangered to Vulnerable.
And so is rh negative blood with around 0.6% of the Chinese population having it.
Here is an article about an rh negative person in China: