Origin: Folkore of Sweden
About King of the Snakes / King of the Serpents
In Swedish folklore, the King of the Serpents is a guardian for all snakes. The warning goes that, should one kill a snake in the audience of other snakes, one must flee or suffer impending death by the terrible and powerful King of Serpents. 
The King of Serpent is a guardian of life. 
The King of Snakes is an enormous wurm with a crested head. 
For more information on footnotes and references, please see the bibliography.