Entrance to a Serpentine Hallway                       -      N      - 
(-------------------------------------------------)     - <---(M)---> -
                                                        -      -     SE

Stepping into this room, the first thing noticeable is that you cannot
see the end of it because of the twists and turns that it takes.  It seems
to snake back and forth like a serpent.  The air is very dusty here also
from the recent cave-in that sealed it off from the rest of the catacombs. 
Listening, you can hear what sounds like boulders falling up ahead.  Before
and moving as if it were alive.  Upon a second closer look, the floor is
covered with snakes and lots of them!  Better watch your step.  
A writhing mass of snakes covers the floor here.
A writhing mass of snakes begins attacking you!
A writhing mass of snakes has several minor wounds and bruises.