Enemies that don't get to make a save against Command

I wonder if anyone has a list of them? Just yesterday I was surprised to know that Ankhegs don't get to save against Command due to their low HD and also fall easily to Sleep. On the other hand, dire/dread wolves are supposed to be higher than 6HD and get to try a save?
As I'm playing a cleric charname for the first time, it would be nice to know a list of nice enemies that have less than 6HD for Command abusing!