Internet star "Grumpy Cat" dies at the age of 7

The famous feline, whose frowning visage endeared her to millions of fans across social media and saw her photographed with celebrities including Stan Lee and Jennifer Lopez, passed away in the arms of her mommy, Tabatha at her home in Arizona.

The mixed-breed cat, whose real name is Tardar Sauce, found fame when a photo of her as a kitten was posted on Reddit in September 2012, her website says.

"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!"

Grumpy Cat has 8.5 million fans on Facebook, 2.5 million followers on Instagram and 1.5 million on Twitter.