While I came up with the bookshroom idea several years ago (the picture above is from Inktober 2018, I'd never properly written anything down about them until today. This is still very much in note form.
Bookshrooms are one of the most valued members of the Squashed Forest. Though they are all of the same family and connected throughout the forest, there are several different family off-shoots, each one with a “mother” and several “children”, and they are prolific breeders. They are known for their natural storytelling ability and are born with whole or part of a story imprinted in a strange language on their gills. As this is one of the only written languages prevalent in the forest, most can read it. While the gills can’t really be “read” by other people until the shroom’s demise, the shroom itself can tell the story out loud very well until then, and the best know how to speak several languages in order to make themselves available to more creatures. Once the child shroom dies (hopefully of natural causes, their lifespan is not particularly long), the “pages” can be salvaged and preserved. The mothers are permanently situated in a location of the forest known as the Library (not to be confused with a lie-berry used for truth spells) and there are usually only about 8 mothers alive at a time as their births are very rare. Each mother will spawn many offspring throughout their life, and the smaller shrooms emerge from the ground near them. They are connected under the earth. Each mother tends to be more prone to creating stories of a certain type, for example a mother born sporting an epic romance novel will usually have children born with more run-of-the-mills-and-boon generic love stories, although every now and then something really juicy might pop up.
While the conditions of the library are adequate for living and breeding, the mothers do enjoy certain treats from further afield; water from a particular pool, flowers, bugs etc., and so have made quite a happy living trading off their children for creatures who provide them gifts. This usually works well for all involved. Forest inhabitants gain a story-telling companion to pass the time with, the child shroom gets to see other parts of the forest, and tell their story potentially multiple times which they love to do, and the mothers get everything they need to keep them satisfied so that they can create more children.
Once something is done with a story which they liked, they will often keep the shroom around as a pet, and if they really liked the story they will have it preserved once they’ve passed. Other times, if they’re not a particularly caring creature, the shroom will be abandoned after they’ve told their story. This sounds cruel, but there are a couple of known dropping off spots where they are left with their own kind. Worst case scenario is that the shroom is destroyed before its time. Most creatures do not understand why this happens, but every now and then pages and chunks of smashed bookshrooms can be found scattered through the forest. There is a rumour that bookshrooms are particularly tasty, but more things stick to eating less sentient fungi.
The passing of a mother is a much bigger affair. They live a lot longer and are usually mourned by most of the forest. The birth of a new mother often happens quite soon before or after the death of one, as even the separate families are connected deep down, but there have been occasions where only one or two mothers existed at a time. Some say there is a grandmother bookshroom deep down under the soil somewhere, but this is probably a myth.