April 29 was Grumpy Cat's birthday party, and fittingly, the famous feline had a party in the Big Apple. The world learned about Tardar Sauce (abbreviated to Tard) in 2012, when the brother of her owner posted a photo of her frowning face on Reddit. Since then, Tard has been memed a million times over, been on the cover of The Wall Street Journal and New York Magazine, grown a huge social media following, and gotten a sponsorship with Friskies Party Mix cat food. Like it or not, cats like Grumpy Cat are basically celebrities.

Once we got the invite to attend Tard's birthday in New York, we decided to bring the cameras out and get to know her owner, Tabatha Bundesen, and her guests. Complex Staff Writer Frazier Tharpe attended "Grumpy Hour" and the #terribletwoturnup that followed. 

RELATED: 30 Things You Didn't Know About Grumpy Cat