Little Nemo was a fictional character in a weekly comic strip by [Zenas] Winsor McCay---ex sign painter, vaudevillian and freelance cartoonist in Cincinnati, Ohio . It appeared in the New York Herald and the New York American newspapers from 1905-1913. It was first called 'Little Nemo in Slumberland' and then 'In the Land of Wonderful Dreams' when McCay changed newspapers.
McCay also penned another comic strip in 1905 [thru 1911]: 'Dreams of the Rarebit Fiend'---under the name of 'Silas.' Both strips featured bizarre, fantastic dreams, always ending with the dreamer suddenly sitting up in bed. But the Dreams strip was aimed at adults with a different adult hero-ing each strip---the dreams resulting from indigestion [usually from Welsh Rarebit], and some say that Nemo was just a children's version of Dreams. The latter included horror and great violence, transformations, embarrassment and other nightmare situations we all can imagine. It was also said to be quite funny.
McCay is also responsible for the perhaps the first three animated subjects, the first one forgettable but based on Nemo, the second called 'How a Mosquito Operates', and the third 'Gertie the Dinosaur'---all painstakingly drawn by hand. The latter, in 1914, was often called the first successful animation, and it led to the cartoon World we see through today. The first and second were used by McCay in his vaudeville act.
Nemo, the comic strip, was often dark and surreal---and some say threatening and violent. The strip covered the dreams of a little Nemo ('nobody"'in Latin), the boy-hero. Nemo 'woke-up' in the last panel of each strip---usually due to a 'dream event' or pending mishap: giant mushrooms, falling from a bridge, or bed with giant legs. In every dream, Nemo was trying to get to Slumberland to play with the Princess, King Morpheus' daughter.
As might be expected, Nemo received a heavy name-tied-merchandising in 1906: postcards, books, games, and children's clothing. He even won a U S Postage Stamp in 1989 and 1993.
Early during its second year, Nemo reached Slumberland, but had to go through months of troubles to reach the Princess. During his efforts, he was constantly awakened by Flip, a 'gentleman' wearing a hat with "Wake Up" on it in big letters. At the sight of Flip's hat, Nemo usually woke up. At first an adversary, Flip later became one of the strip's heroes, along with Dr. Pill, the Imp, the Candy Kid, Santa Claus, the Princess and King Morpheus.
The "Slumberland" of the title had a double meaning: King Morpheus's fairy kingdom and the reality of sleep itself. Nemo's dream-adventures included time in other imaginary lands [as well as Slumberland], the Moon and Mars, and in our own "real" world, made fantastic by his 'slumber-dream-state.'
An operetta based on the strip, was composed by Victor Herbert [of Babes in Toyland fame] with lyrics by Harry B. Smith. A lavish production, the operetta opened in 1908 and ran for 111 performances, closing in 1909. The show introduced a new character to the tale called 'the dancing missionary', who later appeared in several episodes of the comic strip during 1909. It also introduced the word whiffenpoof.
Among the popular songs in the production were: If I Could Teach My Teddy Bear to Dance [Nemo]; Happy Land of Once-Upon-a-Time [Candy Kid]; Is My Face on Straight? [Dr Pill, Flip and the Dancing Missionary]; and Happy Slumberland [Nemo, Candy Kid, Princess, Weather Vane and Betty.]
In the operetta, Little Nemo goes to Slumberland to find the elixir of youth, stolen by Dr. Pill's missionary [from where isn't really known.] Returning home, he goes on several adventures with King Morpheus.
In one scene, three hunters try to out-lie each other with their tall tales about animals [no one ever heard of] they've caught, including: a 'Peninsula' bird that lays square eggs, a creature who lives on canned meat---thus having Armour and is so Swift, it can only be killed by laughing it to death [ala Who Framed Roger Rabbit.]
According to Gerald Bordman [American Musical Theatre: A Chronicle], a backstage problem forced Joseph Cawthorn to adlib on stage, and he made up the story of an animal that lived in water and gobbled its food. And so we met the Whiffenpoof.
In 1909, an a-cappella singing society was formed at Yale, and the in-the-Broadway-know members called the group the 'Whiffenpoof Society.' Not long after, Meade Minnigerod, George Pomeroy, and Todd Galloway wrote the 'Whiffenpoof Song'---[We're Poor Little Lambs...]
This song became famous: as a hit for Rudy Vallee in 1936, and a hit for Bing Crosby with the Fred Waring Glee Club in 1947. Bob Hope and 'der Bingle' also sang the song with a flock of sheep in the movie, 'Road to Bali', in 1953.
Now that I've done the research, I fully expect to meet some of these characters when I fall asleep tonight.