Blue
Ravenous Bugblatter Beast of Traal
Varies if I'm a player or DM.  OAs are serious, but not the end of the world - there are times they should be accepted in order to do something else.  If I'm the DM, I run creatures based on intelligence, aggressiveness, pain tolerance, etc.  Some will, some won't.  As a player, I'm wary of triggering and OA but not afraid of it, but I'm in a minority.
It's a good rule - it really makes everything think.
				
			It's a good rule - it really makes everything think.
				