The internet sensation known as Grumpy Cat, whose real name was Tardar Sauce, passed away on Tuesday and it's possible there will never be another like her, as it's unclear what kind of cat she was.

Editor's note: Grumpy Cat, the feline whose disapproving mug made her the star of internet memes, died May 14 at age 7, her publicist confirmed. (You read that right; this cat was so famous, she had a ...