Antiquated Linguistics: For a very long time, from its creation in 1955 until 1989, the characters all spoke the Flemish dialect. And this while other comics already spoke the Dutch standard language since the 1960s.
Kwak always adds the letter h in front of every syllable. Boemel changes the letter 'b' into a 'p' and a 'd' into a 't'.
Child Prodigy: In "Kinderen Baas" every child becomes a prodigy for an entire album.
Children Raise You: The children raise the adults who became child-like in "Kinderen Baas".
Christianity is Catholic: Jef Nys was a pious Catholic and "Jommeke" was published in Catholic magazines and newspapers. So naturally a lot of Catholic imagery is referenced and seen. Justified since in the Flanders of the Fifties until well into the Seventies, everybody was Catholic.
Just Woke Up That Way: In a few albums professor Gobelijn accidentally puts something in the water or the air that transforms everybody in Zonnedorp (or sometimes the entire world) into a strange mutation, shape or different way of thinking.
In "Kinderen Baas" all the children become as smart as adults and the adults start acting like children.
In "De Lustige Slurfers" everybody gets an elephant's trunk.
In "Het Staartendorp" everybody grows an animal's tail.
In "De Luchtzwemmers" everybody floats up into the air and is able to fly.
In "Neuzen bij de Vleet" everybody's nose grows large.
In "De Vruchtenmakers" everybody grows a tree on their head.
In "De Samsons" everybody's hair grows and they become super strong.
In "De Grote Knoeiboel" everybody becomes a weird shaped character.
Kids Shouldn't Watch Horror Films: In the album "De Vampier van Drakenburg" Filiberke watches a vampire movie while being home alone at night. He is so scared that he actually goes to Jommeke's home to stay over for the night.
Madam Pepermunt, who shoots peppermints instead of bullets, hence her nickname.
Boemel, a tramp who always carries a bottle in his back pocket (boemelen is Flemish for drinking large quantities of alcohol)
Choco the chimpansee is named that way, because he likes to eat chocolate paste.
Mind-Control Device: The Koningin van Onderland hypnotizes a police man in "De Koningin van Onderland" so he can kidnap children to her castle.
Moses in the Bullrushes: In "Het Hemelhuis" a little baby is found floating by in a basket of reeds. Jommeke even says it's like the story of Moses. They adopt the kid until his real parents come to take him with them.
The Movie: In 1965 a very low-budget live-action film was made, "De Schat van de Zeerover": It wasn't a success and is almost forgotten today.
Name and Name: Kwak and Boemel, Annemieke and Rozemieke, Jommeke and Filiberke, Mic Mac Jampudding and Arabella.
Narrating the Obvious: Since this is a comic strip aimed at children a lot of things are explained in this way.
National Stereotypes: All Scotsmen are thrifty. All Native Americans are dressed like in the 19th century, Spaniards add "-os" at the end of each noun. Black Africans are helpless children. All Asians are unable to say the letter "r". Every non-Western country is primitive.
Madam Pepermunt is an American woman who enjoys shooting her revolver and adds "Okay?" at the end of all her sentences.
Mic Mac Jampudding is a Scot who walks around in a kilt and is grouchy and thrifty.
Shaggy Dog Story: In "Wie Zoekt Die Vindt", Jommeke and his friends travel to several places on Earth to search for a treasure, only to find out that it is buried in their own village, where it all turns out to be a simple All for Nothing joke.
In the Urbanus album 30 Floppen Jommeke has a cameo, announcing all the good deeds he will perform that day. In the final panels Urbanus, Amedee and Nabuko Donosor interrupt him, because his Incorruptible Pure Pureness destroys the vulgar atmosphere of his own comic strip.
Single Malt Vision: A running gag in the series is that everyone who first encounters the twin girls Annemieke and Rozemieke thinks he's seeing double.