I have been ambushed by a massive example of a Night Weaver. I need to decisively escape it or kill it before it kills me.

The battle is over. It was too close for comfort but I managed to slay the beast. I have fashioned a crude dagger from one of it's fangs and some silk. My rapier's blade is now stained a deep blue from it's blood, but thankfully it appears to only stain metal.