I've never had the Hunt called on me, though I've seen it chew up other people. Mostly because I play hidey classes and don't touch druids during the full moon. Probably the best defense against the Hunt is to never have it called on you in the first place.

Other thoughts:

Know when your PK range includes a druid with the Hunt. Even the Sylvan ones vis fairly often. Also, many druids are DUMB and keep a Treant by their side at all times. "whe treant" = "whe druid". I bet I could kill people as a druid purely by virtue of NOT having a treant and having other people RELY on me to have one in order to discover my location.

Also, know where they're likely to sit in briars. Large Crossroads. Darien Crossroads. Northern Xroads outside Galadon. Eastern Xroads outside Galadon. Field of Rocks and Brush. Entrance to the Holy Grove. Etc. If it's a full moon or you know a druid is online who's prone to sitting in briars, scan before moving onto those squares. Even if the druid doesn't have a treant you can still see his CoW. (As before, I bet I could kill people as a sylvan druid just by putting my briars in NON-STANDARD locations).

For extra fun, learn what CoW's each enemy druid likes to use. The ones I observed with my last character (and who are still alive) seemed to use the same ones over and over again. Forest Witch, Savage Moorcat, Ogier, Kudzu. If "whe treant" doesn't work, start where-ing for the various CoW's.