By now you’ve surely heard about Grumpy Cat, a feline who has a giant Internet fan base thanks to her permanently miserable expression. Now, not only has Tard, whose full name is Tardar Sauce, taken the net by storm, but also the Austin, Tex.-based festival South by Southwest (SXSW).

According to CNN, Grumpy Cat has been hanging out at the Mashable House, run by the tech news website, at SXSW and drawing huge crowds as one of the most popular guests at the interactive festival. ABC reported that even “hundreds of people waited in line in the pouring rain” just to catch a glimpse at the sourpuss puss. One woman even flew from Australia just to take a photo with the Internet superstar.

Just a few months ago, Grumpy Cat shot to fame when her owners, Bryan and Tabatha Bundesen, posted photos of Tard on Reddit, which went viral almost immediately.

"She was lying in my lap and she looked extremely grumpy so I decided to put it on Reddit," Bryan told ABC News at the festival. "It went viral and I never expected it."

Fans fell in love with the cat’s forever grumpy disposition and Grumpy Cat has become the subject of countless Internet memes, a popular YouTube account, the website, which garners more than 1.5 million unique visitors monthly and Twitter accounts (@RealGrumpyCat and @ItsTheGrumpyCat). One of the accounts has 300,000 followers alone.

"It was an accident," Bryan Bundesen, who manages the cat’s online presence, told CNN of Grumpy’s fame. "We thought it would get some laughs, with the Internet liking cats. And it just kept going."

According to Bundesen, 11-month-old Grumpy Cat, who was adopted in April last year, has a condition called feline dwarfism, which causes her to have “small sighs and stiff back legs,” ABC reported. But not to worry: Tard is a really “healthy and happy cat” despite her expression, according to her owners.

SXSW marks the first public appearance for Tard, who lived in Morristown, Ariz., with Tabatha. But thanks to her overnight fame, Grumpy Cat will soon be featured in a Friskies commercial for cat food. The Bundesens declined to state their exact profits to CNN, but Bryan said Grumpy Cat has brought in “the mid-five figures” worth of cash.

But Grumpy, who has her own managers due to her many press requests, isn’t a fame hoarder. Her owners have also delved into philanthropy, having done work with a no-kill shelter called Austin Pets Alive.

"A lot of people think we are exploiting the cat, we limit her exposure greatly," Bundesen told ABC. "She is only here for an hour at a time. Ninety-nine percent of the time she is just a regular cat. She is not front of the camera at all times, she is a normal house cat and we love her."