Plain white bone containers saying simply “bones” were uncommon loot from several different monster types (harpies, 1 of the 3 but I forget which Ogres/Ettins/Trolls, and other lower tier spawn) but stopped spawning around 2003-4. There are 6 different graphics(I think?). Players requested a return of the containers for deco & they returned with names on Ant Lions. The names were added for deco and to differentiate them from the original non spawning versions. The containers returned again w/o names but in colors for the Prime Evil spawn puzzles. I have a couple full sets for a museum but never got around to putting them out. They’ve never been worth much but for nostalgia they’re kept by some. They may have been available in dungeon chests or elsewhere long ago but all mine came from monster loot so that’s all I could comment on.