Well. (sniff.) I've thought about
the watcher ever since
Frodo talked about it when he was Mayor for a short while.
As far as who controls it, I've never thought about that part. I always just thought it was useful as a back gate guard, like
Shelob was for
Sauron. There's plenty of
evil in
Middle-earth from
Morgoth without need for it all to be controlled by somebody. But it probably does mean something that
Gandalf remarks about it going after Frodo. (If it would have gotten him, I might have gotten
Bag End sooner. (sniff.)) I suppose its worth thinking about why it went after Frodo. Where's my umbrella. I think better when I'm holding my umbrella.