No. No new campaign needed. It took me a while to encounter one, though. Eventually I ran into one around a swampy settlement (which makes sense). It was actually 4 of them roaming around, not a single one lurking at a fixed location. Not sure if there are ones at fixed locales. Despite managing to find one by accident close to the middle of the settlement area, I couldn’t find one at all when I went exploring all the way through the wilds. I’m past day 500 on my current campaign. I’ve uncovered more or less the whole map and have beaten every end-game crisis, but in spite of that and in spite of razing many remote locations and orc camps (and despite bumping into the wurm quite quickly in the end) I still haven’t been able to find a single rare piece of body armour, and therefore am still stuck on the ambition to acquire one each of the rare weapon/shield/armour/helmet collection, which I selected around day 100 (at which point I already had a selection of rare weapons/shields/helmets) before even ending the first crisis …