What is the solution in the clue of the hissing serpent?

The solution in the clue of the hissing serpent is that the serpent is a symbol for the letter "S". This can be seen in the English language as the letter "S" is often written in a similar style to the hissing serpent with a curved line that has a single point at the end. Additionally the hissing sound that a serpent makes is similar to the sound of the letter "S" when it is pronounced. Therefore the solution to the clue of the hissing serpent is the letter "S".