Grumpy Cat is the angriest cat you’ll ever see. She hates everything. Especially fun. “I had fun once. It was awful,” her most famous Internet meme says. Meet Tardar Sauce, the cat whose precious frown has made her famous as “Grumpy Cat.” In an Internet world flooded with adorable or outrageous kitty-cats, “Tard” has made her mark as the grumpiest of them all.