Tolkien's LOTR features such a lake, at the Western Gates of Moria.
Watcher in the Water
"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...
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