I suppose that one could have a dungeon ecosystem macromanaged. Just decide starting populations for each monster species, and come up with some code for adjusting them over time. Of course, the player would need to be able to make their own adjustments to those populations someway (most likely by killing, but leaving food lying around might work too). You could then use those population numbers to decide the spawn rates of the various monsters.
The idea that I mentioned of being able to choose a specific monster and give it a name and/or change the char representing it could have some use in a more traditional roguelike. The player could just be going through the dungeon, when all of a sudden, an elf (represented by e) steals their hat and runs off. However, before then, the player is able to memorize it's features with some special command. The elf ceases to be just an elf. It becomes a unique creature and the player assigns it the name, "Blasted elf that took my hat!" The player even changes the character representing it to "ê". This unique creature will have a chance of spawning in the place of a regular elf and will keep the stats and inventory it had from previous times it has appeared, so that one turn, the player may finally defeat it and reclaim that hat!