Celebrity feline Grumpy Cat passed away on Tuesday morning after suffering from a urinary tract infection, her owner Tabatha Bundesen announced on Instagram.
She wrote: "Despite care from top professionals, as well as from her loving family, Grumpy encountered complications from a urinary tract infection that unfortunately became too tough for her to overcome.
"She passed away peacefully on the morning of Tuesday, May 14, at home in the arms of her mummy, 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."
Grumpy - who received the nickname because Dwarfism and an underbite had caused her to have a permanently disgruntled expression on her face - shot to fame in 2012, when a photograph of her was posted on Reddit and soon went viral.
The much-loved moggy - who is believed to have amassed a fortune of $100 million dollars - released a number of books and made countless TV appearances on shows such as The Bachelorette.
Among her celebrity admirers was the late 'Marvel' comic book legend Stan Lee, who posed for several pictures with the famous feline.
At the time of her death, Grumpy had 2.4 million followers on Instagram.