The Internet knows her as “Grumpy Cat,” but Tardar Sauce — “Tard” for short — isn’t actually all that grumpy.

The mixed-breed cat became an Internet sensation when her photo was posted on Reddit in September. Many users suspected that the feline’s frown had been Photoshopped, so her owners shared some videos of her to prove that Tardar’s face really does look a bit cranky.

Grumpy Cat meme“Tardar has what looks kind of like an underbite,” owner Tabatha Bundesen of Morristown, Ariz., told Fox News. “She looked unique, as did her brother, at birth, with a flat face, bubble eyes, and a short tail.”

Tardar was born on April 4, 2012, and although she’s said to have some ragdoll, snowshoe and Siamese in her line, her mother is a calico cat and her father is a gray-and-white tabby cat.

“Many have said that she is a 'dwarf' cat or a 'munchkin,' but she was born from two normal-sized cats,” according to Grumpy Cat’s official Facebook page. “Her back legs are a bit longer than her front legs and she wobbles a bit when she walks.”

Veterinarians say her size and shape could be genetic or neurological, but that the cranky kitty is perfectly healthy.

Although Bundesen usually gives away kittens, her 10-year-old daughter, Chrystal, fell in love with Grumpy Cat’s unique appearance and insisted they keep her.

As a kitten, Tardar’s fur was speckled with dark spots, which reminded Chrystal of tartar sauce. She named the cat after the condiment — misspelling it in the process — and it stuck.

But despite her distinctive frown and inherent clumsiness, Tardar’s owners say she’s a sweet and affectionate pet.

“Tardar is not as coordinated as a normal cat, so she is likely a little angry about that. I think she likes to be held and petted sometimes, but being the pet of a 10-year-old could make anyone grumpy,” Bundesen said.

Recently, Tardar decided to set the record straight about her disposition and released the video below in which she clarifies, "I'm not grumpy. I don't like when people call me grumpy. That's just how my face is shaped. I look like other cats, I think."