Out from the water a long sinuous tentacle had crawled; it
was pale-green and luminous and wet. Its fingered end had
hold of Frodo's foot, and was dragging him into the water.
Sam on his knees was now slashing at it with a knife. The
arm let go of Frodo, and Sam pulled him away, crying out
for help. Twenty other arms came rippling out. The dark
water boiled, and there was a hideous stench.
[ The Fellowship of the Ring, by J.R.R. Tolkien ]