The Watcher in the Waters is a creature / character in the 2001-03 film series, The Lord of the Rings. It only appeared in The Fellowship of the Ring. It is a Kraken-like creature that lives in Moria's waters and guards the gates. It was woken up by Merry Brandybuck and Pippin Took after they threw rocks in the water and attacked the Fellowship and later trapped them inside the caves.
The Watcher is based on the same creature from the book by J. R. R. Tolkien with several elements of the Kraken from nautical mythology.