You hold your nose and step forward into the slimy water.
A couple of steps in, you feel a pulling on your leg.
Lifting it out of the water you find that some sort of vine has coiled itself around your leg.
You leap back to the bank and the vine remains fixed.
From out of the water, one end of the vine rises,
moves around in the air as if looking at you,
and then falls back with a splash.
You realize that this is not a vine,
but a long SEWER SNAKE, which is now pulling itself towards you.