Umber hulks are one of my go-to-scary-underground-monsters in part because I chitter pretty well.  I kind of pulled this little problem out of nowhere because there were some cascading fails, so I wanted to give something pretty scary.<br/><br/>With everyone invisible though, your first hit counts as an automatic 10+!  So Sain, if you'd prefer to do /more/ damage, you can add a +1d6, but then it will hit you back as though it were a 7-9.