Just speculating here, but it seems to me to have a high level basic D&D feel to it, possibly like something from the Master Set or perhaps the Immortal Set modules or maybe even from the DA-Blackmoor series. I pulled all my Basic D&D stuff out tonight to check to see if I could find it, but everything I checked either didn't have it or it was shrinked.

Hopefully someone else can maybe check their stuff also, to see if my suspicions are correct.
"He who fights with monsters might take care lest he thereby become a monster. And if you gaze for long into an abyss, the abyss gazes also into you." -Neitzche