Grumpy Cat, the Internet celebrity famous for her perpetual scowl having one of the most popular memes has passed away.

The family owning Grumpy Cat posted the news on Twitter earlier on Friday, stating “Grumpy encountered complications from a recent urinary tract infection that unfortunately became too tough for her to overcome.”

Grumpy Cat was seven years old.

The twitter post by the family read “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.”

Grumpy Cat's real name was Tardar Sauce.

The owner’s brother, Bryan Bundesen, made the cat famous by taking her photo and posting it on Reddit on Sept. 22, 2012, when the cat was only five months old then.

To put an end to the rumours that the cat’s image had been doctored, the owner posted Tardar Sauce's videos on Youtube.

The cat’s perpetually frowning visage quickly became an Internet meme and is typically accompanied with phrases like “This is my happy face” or “If you’re happy and you know it, go to Hell.”

The owners of the Sauce claim, on their Grumpycat web site, that they don’t know the cat’s breed. They attributed her small size and perpetual scowl to “feline dwarfism.” But they make a point of saying she was not “bred purposefully” as a “munchkin cat.”

The cat owes its real name to a misspelling of the word “tartar” by the owner’s daughter, who believes the cat’s fur resembles the colour of tartar sauce.