鲇鱼上竹竿

Pinyin: nián yú shàng zhú gān Explanation: 俗说鲇鱼能上竹竿，但鲇鱼黏滑无鳞，爬竿毕竟困难。后以之比喻上升艰难。 Thesaurus:  Silurid along Bamboo, Silurid On bamboo, Fish pole