The cat from Arizona had "helped millions of people smile". Grumpy, whose real name was Tardar Sauce, went viral in 2012 after photographs of her sour expression emerged online. Her image quickly spread as a meme. According to owner Tabitha Bundesen, her facial expression was caused by feline dwarfism and an underbite.

Why was grumpy cat grumpy?

She was known for her permanently "grumpy" facial appearance, which was caused by an underbite and feline dwarfism.

Why are some cats so grumpy?

The good news is that cranky behavior in cats is often is temporary and can be resolved. Aggressive behaviors in cats usually stem from some form of stress. ... Also, if a cat has a sore spot on his back, he may become grouchy with anyone who touches it. This is normal for any pet—and even people!