I am inspired by 's Chinese autonomous flags that I had made my own. I adapted it from the Soviet flag from Wikipedia.
This is the flag of the Tibetan Soviet Socialist Republic, established in 1947 after the Sino-Mongolian-Manchurian war in which the Nationalist Chinese were exiled to Taiwan by the Soviets and the CCP for attacking Outer Mongolia. As a result, the Soviets not only set up a communist regime in China Proper, but annexed Xinjiang and Tibet excluding Kham. The reunited Mongolia and Manchuria remain separate puppet states. Mao was not happy for it, but had to swallow his pride.