The Art of War by active 6th century B.C. Sunzi

29. The skilful tactician may be likened to the _shuai-jan_. Now the

_shuai-jan_ is a snake that is found in the Ch‘ang mountains. ["_Shuai-jan_" means "suddenly" or "rapidly," and the snake in question was doubtless so called owing to the rapidity of its movements. Through this passage, the term in the Chinese has now come to be used in the sense of "military manœuvers."] Strike at its head, and you will be attacked by its tail; strike at its tail, and you will be attacked by its head; strike at its middle, and you will be attacked by head and tail both.