This is what we found on Wikipedia regarding the Big Fat Festival:

The Big Fat Quiz of the Year is an annual British television programme broadcast at the end of the year on Channel 4. The show is a comedy panel game in the style of a pub quiz. Three teams of two celebrities, mostly comedians, are asked questions about the year gone by in various categories, writing answers on an electronic board in front of them. At the end of each round the answers are displayed and points awarded.

The first edition was broadcast on the 28th December 2004 and it has been held every year since on approximately the same date in December. An exception to this has been the years of 2009 and 2010 when it was held in early January of the following year. In November 2007 the first special edition aired for Channel 4's 25th anniversary celebration. Three special editions then aired in September 2012, to celebrate Channel 4's 30th anniversary and the questions that were asked in each episode were about a particular decade. A second set of 'decades' editions screened in September 2013 and a special edition to mark the 10th anniversary of the Big Fat Quiz aired in January 2015.

A new series titled the Big Fat Quiz of Everything first aired in January 2016 and the questions were based on a broad range of subjects including history, geography, sport, film, television, science, technology, music, art and literature.

Stand-up comedian Jimmy Carr has been the host and quizmaster of each edition to date and Richard Ayoade and Jonathan Ross have made the most appearences with 21 each. Repeats can usually be found days later on Channel 4's sister channel E4 and/or 4seven and Channel 4 has made full episodes of The Big Fat Quiz of the Year available to view on All 4.