Grumpy Cat's not smiling over another best seller

One frowning feline had a lot to celebrate this World Cat Day.

More than 1000 people lined up in a New York bookstore to meet the online sensation, Grumpy Cat.

Her appearance was part of promotion for her second book, “The Grumpy Guide to Life: Observations by Grumpy Cat”.

Her first, “Grumpy Cat: A Grumpy Book”, spent 10 weeks on the New York Times bestseller list. 

Grumpy Cat, whose real name is Tardar Sauce, shot to fame in 2012 after pictures of her were posted on social media.