Last year I showed the Binche carnival at http://whatisbelgium.blogspot.be/2012/02/binche-carnival.html. Binche is located South of Brussels in the French speaking part of the country.
As with most things Belgian, the equivalent can be found on the other side of the linguistic border. I therefore had to drive Northwest of Brussels this year to the Flemish counterpart of Binche, to a town named Aalst (or Oilsjt in dialect - see last photograph) where they have been celebrating carnival since 1443 or so the earliest records indicate.
The last picture shows an onion, symbol of Aalst because of the large number of onion farmers which the region had in the past.