From Wikipedia:
Xu Xiaodong (Chinese: 徐晓冬; born 15 November 1979), nicknamed “Mad Dog“, is a Chinese mixed martial artist (MMA) who has been called the founder of MMA in China and is known for taking down fake martial artists. He gained prominence online after he was filmed defeating a self-proclaimed tai chi master in 2017.
Xiaodong is also very active on social media. Some describe him as arrogant and disrespectful, but he is actually more of a person who doesn’t mince his words. He is particularly entertaining with his self-deprecating humour and no-holds-barred comments and criticisms on Chinese society. However, the one topic he avoids is politics. Perhaps that’s why he hasn’t gotten into trouble with the authorities yet.