By saying the magical phrase, "Hiss" given to him by the King of the Snakes, the wander was able to turn into a snake himself. He was able to use the form of a snake to get into a crevice, to access an underground tunnel that lead to a gnome's house.
Behind the scenes[]
The spell Hiss can be used at any time, anywhere in the game. It will turn the player character into to a snake every time. There are no limits to the use of the spell. However the spell is only useful in one location.