I followed the instructions on the guide (used pizza to feed the mouth, take the wood, light it, guide it up to the fire under the cookpot, click on the 6 mushrooms that appear to put them into the cook pot). My pot then spins around, but no eternal.
I tried exiting the game and reentering, but the problem persists (plus my number of eternals is down to 90 when I restart the game, rather than 99).
Since no one else seems to be suffering this problem I have no idea what I can do to fix it :(