The book follows a typical day for Fungus the Bogeyman, starting when he wakes up and ending just before he falls asleep. As his day progresses, he undergoes a mild existential crisis, pondering what his seemingly pointless job of scaring surface people is really for. He is a member of the Bogey society, which is very similar to British society, but Bogeymen enjoy things which humans (called Drycleaners because of their contrasting environmental preferences) would not be comfortable around; for example darkness, damp, cold and over-ripe food. The book depicts the mundane details of Bogey life in loving detail, with definitions of Bogey slang and numerous annotations concerning the myths, pets, hobbies, literature, clothing and food of the Bogeys.
The book masterfully combines a thorough anatomy of Bogeyworld with a meditation on the futility of existence. As Fungus moves slowly through his day (or, I should say, his night, since Bogeys are nocturnal), he is given to such reflections as "Not to reason why... not ask questions... just keep bogling away".
Fungus is a great book for parents to read to their children as they will get just as much joy from it as their kids. Whilst the young ‘uns will enjoy all the frights and horrible tricks that Fungus gets up to, adults will see another layer of wit on top of this in the way Fungus’ job and world is perhaps not quite so different to our own as it first appears.
It has been called "the nastiest book ever published for children," and it stands in a pivotal position among the picture books of the British artist-writer Raymond Briggs. Fungus the Bogeyman (1977; first American edition 1979) offers both the most fully developed fantasy and the most outrageous affront to conventional mores of all Briggs's children's books to date. It also marks the midpoint of a philosophic curve Briggs has been tracing from the cheerful confidence of Jim and the Beanstalk (1970), to the black despair of When the Wind Blows (1982). A close look at Fungus reveals the common concerns that tie these two extremes together, and that make the last book a wholly logical development from the first.
Bogies, according to K.M. Briggs's Encyclopedia of Fairies, comprise "a whole class of mischievous, frightening and even dangerous spirits whose delight it is to torment mankind." From this basis in folklore, Raymond Briggs has postulated a race of large, blobby, green-skinned beings who inhabit their own underground world. At night (their day), the Bogeymen emerge to carry on their "work"—frightening human beings with mysterious footsteps, scrapings on windowpanes, and an occasional graveyard appearance; they also cause boils. But we see the daily life of Fungus at home too, eating breakfast with his wife and son, bicycling off to work, and stopping off at a pub on the way back. Meanwhile, as an anonymous narrator fills in a complete picture of Bogeydom, lecturing in academic style on Bogey culture, sports, flora, fauna, and anatomy, Briggs utilizes the full subcreative power of fantasy, supposing not only magical powers (as he does in Father Christmas and The Snowman), but a race of imaginary beings and their entire world.
Fungus is Briggs's most deeply fantastic book for children and his most startling. Indeed, both in form and in content, it could scarcely be better calculated to repel the adult reader—or intrigue the young one.