Healers have a reduced chance to engrave a given character in the dust correctly, because of the stereotype about doctors having terrible handwriting.

Add in master lichens as a real monster, which are only a bit more threatening than normal lichens (maybe speed 2 or 3, have a passive sticky attack like mimics) but have an increased difficulty so that they generate deeper in the Dungeons, and are a source of nonrotting corpses. Possibly, the passive sticky attack should also be given to regular lichens.