Works of the third group are mostly about modern topics, such as "Playing Table Tennis," "Playing Volleyball" and "Weightlifting," that are all all vivid and lifelike.
Reflective works with a touch of humor and sarcasm fall under the fourth category. A case in point is the interesting and thought-provoking "Puffing the Cow," which features two monkeys, each with a pipe in the mouth, puffing toward the cow's ass to see who can puff it bigger.
The last category includes works on historical and theatrical stories, all of which contain vivid images with deep and profound meanings.
Hairy monkeys actually disappeared during the period between 1940s and 1980s, so when Cao's works showed up at an exhibition of folk artworks in 1983, many old Beijingers got extremely excited.
The rebirth of hairy monkeys also attracted a number of new lovers, both old and young, who asked about the making method via writing or telephoning. Some even visited Mr. Cao in person, exchanging what they have learnt from their working with the hairy monkeys. The styles of their works vary a lot: the young people have created the discoing toys while the farmers have come out with a series of rustic ones.
Due to his old age, Cao is now incapable of making hairy monkeys. As a way of promoting the art, he is sharing his experience with his followers without preservation. Today, a number of artists are working with him to carry on and develop the folk art, a treasure unique to Beijing.