Some of the rats or direrats (hard to tell which) have demon voice set with booming voice. I presume the rats are not possessed... even if they are vile.
Yeah... This has something to do with 1.69, I think they screwed up the 2da.
Aren't the rats unique blueprints (not default Bioware ones), so you can change the line they use? I think next patch is a bit unlikely at this point.
Not the ones with demon voice. They are "Dire Rats" Bioware template creature.
Personally, I enjoy the odd dire rat booming 'I will rend your soul!'. >.>