-Xeroc's can pose as any item, even the amulet. Strangely, I don't think they become an item if you find them sleeping, since I have came across a few as such.
-Dragons with there fire blast makes it hard to attack from a range, use cancellation if you have, if not I think it is best to run, or try to take it on mono-a-mono/hand-to-hand.
-Bat's move in an almost erratic manner, and seem to be in some other time line or something since sometimes they are slowed, and you can attack several times, and other times they can move two spaces. Seems like they are permanently confused or something, but ultimately head for you.
-Orcs can pick up gold from the floor, so you might be able to get some cash off of them if you kill them, so good idea to gun for them when you see one.