Travel: Mud Bowl
The first thing you’ll notice about this area is the nauseating fog that permeates the air here, forcing your characters to make a [Fortitude 17] save every round, becoming nauseated if they fail. A nauseated character is severely hampered, but fortunately you can simply wait out the effects of the nausea after which your characters will have acclimated to the environment.
When you’ve got your churning innards under control, venture north and you’ll spot some Black Rattlecap mushrooms - the fungus the Old Beldame requested. You’ll need ten of these mushrooms, and unfortunately the area is home to a Tendriculos, a shambler-like beast that prowls around the center of the area.
Not only does the Tendriculos hit for between 20-30 damage, but it gets multiple attacks per round and has a high enough Attack bonus to challenge all but the most optimized tanks. You know how this plays out: if you attempt to fight the Tendriculos without buffing, you’re probably going to have a bad time. If you buff yourself (including the all-powerful Haste) you might just come out of the fight completely unscathed.
If you smite the Tendriculos you’ll be rewarded with a hefty influx of XP, probably more than the thing is worth, if we compare it to one of the Greater Enraged Owlbears from earlier. Oh well, don’t look gift XP in the mouth - take it and enjoy the progress towards the next level. Such spikes are rare enough.
You’ll also be free to search the area for the ten Black Rattlecaps you need. No need for instruction here, there’s fourteen of them spread about and you only need ten, so you don’t even need to be particularly vigilant. Grab the mushrooms you need, then search some foul water along the western end of the map to find some loot, consisting of two Potions of Enlarge Person, a Potion of Blur, 89 GP and a Frost Battleaxe +1 among other, less valuable items.
With the ten Black Rattlecap mushrooms in hand, it’s time to leave. For the sake of continuity the reward for turning these mushrooms into the Old Beldame will be listed below, but the delivery will be left up to your own initiative. Don’t bother going out of your way to do so now; you’ll get an opportunity to swing by later, likely on your way to the Dwarven Ruins.