For those wondering, we didn't die mostly due to a well-placed Disintegrate. My "stick an immovable rod in its innards" was disappointingly low damage.
For those wondering otherwise, our best plan involved turning it into a regular worm, using an immovable rod with a hole drilled through the length of the staff, clicking the rod, then dispelling polymorph.
To my credit, the reason I was hiding was to find out if some guys we'd joined while traveling were sus.
They were sus. Which we found out when they ambushed us at night.
Seriously though the barbarian in our party is the only one with a positive intelligence score.
My favorite character to play was a cleric with just the worst bedside manner.
