Marols

Marols or Marollien (also known as brusseleer, brusselair or brusseleir) is a nearly-extinct dialect spoken in Brussels. It is essentially a heavily-Francisized Brabant Dutch dialect that incorporates a sprinkle of Spanish that dates back to the rule of the Low Countries by the Habsburgs (1519-1713). Its name refers to a district of Brussels called Marollen (Marolles), a neighborhood in the south-central municipality of Brussels, not far from the Palace of Justice. The district takes its name from the former abbey of the nuns Maria Colentes ("Marikollen"). It was a working-class neighborhood but has become a fashionable part of the city. Marols is described as "totally indecipherable to the foreigner (which covers everyone not born in the Marolles) which is probably a good thing as it is richly abusive."
The Royal Theatre Toone in Brussels puts on puppet plays in Marols.
What is Marols?
There is a dispute and confusion about the meaning of Marols, which many consider to be a neighborhood jargon distinct from a larger Brussels Dutch dialect, while others use the term "Marols" as an overarching substitute term for that citywide dialect. According to Jeanine Treffers-Daller, “the dialect has a tremendous prestige and a lot of myths are doing the rounds.”
Origins.
A local version of the Brabantian dialect was originally spoken in Brussels. When the Kingdom of Belgium was established in 1830 after the Belgian Revolution, French was established as the only official language of the kingdom. French was therefore primarily used amongst nobility (however some in the historic towns of Flanders were bilingual and stayed attached to the old Flemish national literature), the middle class and a significant portion of the population whose secondary education had only been delivered in French.
French then gradually spread through the working classes, especially after the establishment of compulsory education in Belgium from 1914 for children aged between six and fourteen years. Primary school education was given in Dutch in the Flemish regions and in French in the Walloon regions. Secondary education was only given in French throughout Belgium. Drained by the personal needs of the administration, many new working class arrivals from the south of Belgium, again increased the presence of French in Brussels. Today, French is the primary language used in Brussels. 
Informal language was from then on a mixture of Romance and Germanic influences, which adapted into becoming Marols.
Examples.
An example of Marols is:
Marols and "The Adventures of Tintin".
For the popular comic series "The Adventures of Tintin", the Belgian author Hergé modeled his fictional languages Syldavian and Bordurian on Marols, and modeled many other personal and place-names in his works on the dialect (e.g. the city of Khemkhâh in the fictional Middle Eastern country of Khemed comes from the Marols phrase for "I'm cold"). Bordurian, for example, has as one of its words the Marols-based "mänhir", meaning "mister" (cf. Dutch "mijnheer"). In the original French, the fictional Arumbaya language of San Theodoros is another incarnation of Marols.