Tardar Sauce, popularly known as Grumpy Cat because of her seemingly glum expression, has died, her family said on Friday (May 17).
Grumpy Cat's family announced on Instagram and Twitter that the seven-year-old feline died on Tuesday due to complications from an infection.
"We are unimaginably heartbroken to announce the loss of our beloved Grumpy Cat. Despite care from top professionals, as well as from her very loving family, Grumpy encountered complications from a recent urinary tract infection that unfortunately became too tough for her to overcome," read the Instagram post.
"She passed away peacefully on the morning of Tuesday, May 14, at home in the arms of her mommy, Tabatha.
"Besides being our baby and a cherished member of the family, Grumpy Cat has helped millions of people smile all around the world - even when times were tough.
"Her spirit will continue to live on through her fans everywhere."
The post was signed off by her family, Tabatha, Bryan, and Chyrstal.
The post garnered more than 35,000 likes in less than an hour, with tributes and condolences pouring in on social media.
"Rest in peace, darling. Your scowl towards me was one of the best moments of my life," Hollie-Ann Brooks posted on Twitter.
Grumpy Cat achieved internet fame in 2012 after an image of her went viral, with users generating many memes and altered images. She went on to appear in films, TV shows, conventions and red carpet premieres.
"Her petite size and famous face is likely due to feline dwarfism and her rear end wobbles a bit when she walks due to this; otherwise she is a perfect little kitty!" her website says.
Despite her permanent frown, she was "super cute and cuddly".
Grumpy Cat has 8.5 million fans on Facebook, 2.5 million followers on Instagram and 1.5 million on Twitter.
In January, Grumpy Cat won US$710,000 in court after a deal between her owner, Tabatha Bundse, and Granade Beverage, turned sour.