In Chinese there are these jokes which are delivered as a small riddle followed by the answer. They are often used humorously, with the answer used as an insult. Here are some examples:
Do they have a proper name? Where did they come from? Is there any regionality with these, or are they encountered across all Chinese languages?
歇后语
≪xiehouyu≫, witty folk simile (popular witty or humorous simile consisting of two parts, of which the second is the "punch line" and is often left unsaid because the listener is assumed to be familiar with it)
We have this in English as well: •Make like a banana—and split •Make like a tree—and leave (Although I'm not sure what we call these in English)
a two-part allegorical saying, of which the first part, always stated, is descriptive, while the second part, sometimes unstated, carries the message, e.g. 泥菩萨过河-自身难保 like a clay idol fording a river-hardly able to save oneself (let alone anyone else)
The Chinese Wikipedia entry for xiehouyu has a 粤语常见歇后语 and 客家话歇后语 sections - so while some xiehouyu certainly are regional - and every topolect has them - the ones in dictionaries or that are "well known" will be understandable everywhere.
it's kind of metaphor, but short and well-known. Sometime it's may pointing a issue by referring a similar situation of metaphor. or sometime it used for just emphasizing the point
歇后语. baike.baidu.com/view/453.htm?fr=aladdin