A writhing mass of....something?

It isn't so much something that grabs your leg, but a whole bunch of somethings that wrap around your ankle and draw you deeper. Your arms flail as you try and grab hold of some nearby roots but their slick coating of mud makes them impossible to hold onto for long. It looks like your adventure is off to a wet and slippery start as you’re pulled to the deeper parts of the water and swept off your feet. You realise that you’re not being pulled deeper down as you worried but are instead being carried along the surface of the water and into an area of surprisingly high water quality.

The quality of the water is the last thing on your mind as once you stop panicking about drowning you're left looking at the roiling and sloshing pool of water that your ankle assailant is pulling you towards. Its not yet completely clear to you what’s over there and your mind races to try and make sense of the few things you do catch a glimpse of, a flash of something here, a small wriggling wormlike thing there. As you draw closer you make sense of it and to your horror, and part arousal, you see that it’s a bunch of…!!