Jansson is principally known as the author of the Moomin books – stories for children that involve Jansson's creations, the Moomins. They are a family of trolls who are white, round and furry in appearance, with large snouts that make them vaguely resemblehippopotamuses.
The first Moomin book, The Moomins and the Great Flood, was written in 1945. Although the primary characters are Moominmamma and Moomintroll, most of the principal characters of later stories were only introduced in the next book, so The Moomins and the Great Flood is frequently considered a forerunner to the main series. The book was not a success (and was the last Moomin book to be translated into English), but the next two installments in the Moomin series, Comet in Moominland (1946) and Finn Family Moomintroll(1948), brought Jansson some fame. The original title of Finn Family Moomintroll, Trollkarlens Hatt, translates as "The Magician's Hat".
The style of the Moomin books changed as time went by. The first books, up to Moominland Midwinter (1957), are adventure stories that include floods, comets and supernatural events. The Moomins and the Great Flood deals with Moominmamma and Moomintroll's flight through a dark and scary forest, where they encounter various dangers. In Comet in Moominland, a comet nearly destroys the Moominvalley (some critics have considered this an allegory of nuclear weapons[8]). Finn Family Moomintroll deals with adventures brought on by the discovery of a magician's hat. The Exploits of Moominpappa (1950) tells the story of Moominpappa's adventurous youth and cheerfully parodies the genre of memoirs. Finally, Moominsummer Madness (1955) pokes fun at the world of the theatre: the Moomins explore an empty theatre and perform Moominpappa's pompous hexametric melodrama.
Moominland Midwinter marks a turning point in the series. The books take on more realistic settings ("realistic" in the context of the Moomin universe) and the characters start to acquire some psychological depth. Moominland Midwinter focuses on Moomintroll, who wakes up in the middle of the winter (Moomins sleep from November to April, as mentioned on the back of the book), and has to cope with the strange and unfriendly world he finds. The short story collection Tales from Moominvalley (1962) and the novels Moominpappa at Sea (1965) and Moominvalley in November (1970) are serious and psychologically searching books, far removed from the light-heartedness and cheerful humor of Finn Family Moomintroll.
After Moominvalley in November Tove Jansson stopped writing about Moomins and started writing for adults. The Summer Book is the best known of her adult fiction translated into English. It is a work of charm, subtlety and simplicity, describing the summer stay on an island of a young girl and her grandmother.
Besides the Moomin novels and short stories, Tove Jansson also wrote and illustrated four original and highly popular picture books: The Book about Moomin, Mymble and Little My(1952), Who will Comfort Toffle? (1960), The Dangerous Journey (1977) and An Unwanted Guest (1980). As the Moomins' fame grew, two of the original novels, Comet in Moominland and The Exploits of Moominpappa, were revised by Jansson and republished. (Source Wikipedia)
Thingumy and Bob (Swedish: Tofslan och Vifslan - tofs, "tuft"; dialectical vivsa, "tuft," cf. vifta, "wave"; compare the names of Tove Jansson and Vivica Bandler,Finnish: Tiuhti ja Viuhti) - Two little creatures who turn up in Moominvalley with a large suitcase, which contains the King's Ruby. They speak a strange language (with "-slan" appended to the ends of some words in the Swedish original, which became spoonerisms, e.g. :"'Man you cake it out?' asked Thingumy. 'Mot nutch,' said Bob", in the English translation) and are pursued by the Groke who wants the contents. They upset Moominmamma by stealing her handbag. They eventually return it and the whole family throws a party to celebrate. The Hobgoblin arrives when Thingumy and Bob open the suitcase, exposing the King's Ruby for all to see. While they didn't give him the ruby, when the Hobgoblin gave everyone there a wish they wished for the Hobgoblin to have a ruby as beautiful as theirs; the Queen's Ruby.