Sam Simon, a co-creator of the long-running hit animated series 'The Simpsons,' has died after a battle with colon cancer at the age of 59, his agent said.
Simon won nine Emmy awards for his work as a writer, director and executive producer of 'The Simpsons'.
Ricky Gervais, who like many celebrities has appeared on the popular cartoon, tweeted a tribute.
Simon was diagnosed with terminal cancer in 2011 and channelled much of his personal fortune into social causes including animal welfare.
After stints writing for Taxi, Cheers and The Tracey Ullman Show, Simon helped launch The Simpsons in 1989.
He left the series after its fourth season under a deal that rewarded him with ongoing royalties from the show, which remains in production.
He established the Sam Simon Foundation, which rescues dogs from animal shelters and trains them to assist the disabled and also funded a Los Angeles food bank.
The Simpsons have paid tribute to US talk show host David Letterman, who announced he will retire from his programme next year.
The one minute clip shows Homer and his family overcoming a security guard and traffic jam as they make their way to the 'Late Show with David Letterman'.
The sequence then ends with Letterman's longtime bandleader Paul Shaffer conducting a version of The Simpsons theme tune.
Letterman, 66, who began hosting the show in 1993, said he will step down in 2015 which led to tributes from celebrities and US President Barack Obama.
The Simpsons will pay tribute to Marcia Wallace, the actress who famously voiced teacher Edna Krabappel in the show, with a special farewell scribble on the school's blackboard - by Bart.
In the opening sequence of Sunday night's episode, Bart writes: ‘‘We’ll really miss you Mrs. K".
The 70-year-old actress died last month and played the Springfield Elementary School character for over 20 years.
The show's executive producer, Al Jean, said plans are in place to retire Wallace's "irreplaceable" Ms Krabappel personality.
In a statement on the death of Marcia Wallace, executive producer Al Jean, said on behalf of The Simpsons:
The statement was posted on Facebook.
Marcia Wallace, the voice of teacher Edna Krabappel on "The Simpsons," has died.
Simpsons executive producer Al Jean said in a statement Saturday that her death is a terrible loss. He says Wallace's "irreplaceable character" would be retired from the show.
The longtime TV actress' credits ranged from playing a wise-cracking receptionist on The Bob Newhart Show to appearances on Candice Bergen's Murphy Brown.
Marcia Wallace, the woman who voiced the character of Edna Krabappel in The Simpsons has died aged 70, according to TMZ.
According to the news agency, the actress had been sick for the past few months and died with her family by her side. Wallace's work playing the cynical Mrs Krabappel won her an Emmy award in 1992.
Mexican film director Guillermo del Toro has been let loose on The Simpsons and directed an eery intro for the show's 24th Treehouse of Horror Halloween episode.
Del Toro, whose films include Blade II and Hellboy, turns the town of Springfield into a place where evil forces have taken over, zombies and monsters reside and nightmares are a reality.
There are around 30 to 40 direct horror movie references in the opening couch gag sequence, including Alfred Hitchcock), Del Toro's 2006 film Pan's Labyrinth and The Shining.