Icelandic actor Stefan Karl Stefansson, who played LazyTown villain Robbie Rotten, has died aged 43 from cancer.
Stefansson was best known for his role on the children's show, which was produced from 2004 to 2014.
He was initially diagnosed with bile duct cancer in 2016, but said it had been removed with surgery.
He often shared his treatment and progress with fans online on social media - announcing in March the disease had returned and was inoperable.
"It's not until they tell you you're going to die soon that you realise how short life is. Time is the most valuable thing in life because it never comes back. And whether you spend it in the arms of a loved one or alone in a prison cell, life is what you make of it. Dream big," he posted to Twitter.
In June his wife Steinunn Olina Thorsteinsdottir revealed the father-of-four's cancer was in its final stages.
A post on Tuesday paid tribute to her husband, and said the family would follow his wishes to scatter his remains at sea.
"Stefan's family wants to express their gratitude for the support and warmth received in recent years, and to express their deepest sympathy to the many friends and fans of Stefan Karl," she posted.
The actor spent his early career working in film and theatre - playing the title role in How the Grinch Stole Christmas in the US from 2008-2015.
LazyTown was produced from 2004-2007, with more episodes made in 2013 and 2014.
It followed the life of a pink-haired eight-year-old girl named Stephanie and her superhero companion Sportacus, who attempt to liven up an inactive town she moved to.
The character of Robbie Rotten was the show's villain and attempted to thwart their schemes, preferring to stay unhealthy.
The show, produced in Iceland, was translated into dozens of languages and aired in more than 180 countries worldwide.
Fans who grew up with the show shared their sadness at the news of Stefansson's death on social media.
This has been literally the saddest day on the internet since Satoru Iwata passed away. Rest in Piece, Stefan Karl (aka Robbie Rotten).— Crimson Mayhem (@mayhem_crimson) August 22, 2018
I spent many hours with my younger siblings watching you years ago and ive lost count of how many times you made us laugh and smile uncontrollably. Thank you for all the joy you brought us and people everywhere.— SMG4 (@smg4official) August 22, 2018
Rest in Peace Robbie Rotten. pic.twitter.com/0lXwMc7miX
Farewell, Robbie Rotten. Hope you finally get to be lazy without those pesky kids exercising around you 24/7. You were a fantastic, funny character. RIP Stefan Karl Stefansson pic.twitter.com/A9GazKA0sL— Jon Bailey (@EpicVoiceGuy) August 22, 2018
The character's popularity has continued online in recent years, where his exuberant facial expressions are frequently used in memes.