I believe that one of the many reasons of the long-lasting love between ADOM and its players is the way this game can surprise you even after so many years of playing (and of reading spoilers). Trust ADOM to still manage not only to throw Easter eggs in my face, but also to do so in one of the features I like and use the most, i.e. the monster memory:


Of course someone already found this, surely a long time ago: a quick search on the wiki reveals the gems hidden in the monster memory. Still, (re)discovering such things on your own always makes for a pleasing experience.