I know what you mean, but in terms of old asian martial arts movies, he looks exactly like those "underdogs" in the movies presented by guys like bruce lee who got offended by "western muscle machines" like chuck norris..
It was a joke, seriously speaking I never considered Bruce Lee the underdog in his confrontation with Chuck Norris, like I don't consider the guy in your video the underdog. It does even take to be an expert to see that the fat guy not only that he is drunk but he is also in terrible condition. Hands up who expected the fat one to win here.