LITTLE ROCK, Ark. (KTHV) -- You may have heard of her, and you may recognize her, but Lil BUB is more than just an Internet sensation.

According to her website, BUB was the runt of a feral litter in rural Indiana. It was apparent early on that she would need special care, but her caretakers call it a "happy accident".

In a new YouTube video, it shows an amazing new feat for BUB: walking. BUB has been immobile for the past two years due to an extremely rare bone condition called osteopetrosis.

Starting in late 2012, BUB started to slowly but surely begin to move. By April 2013 she was walking, running by September, and then climbing stairs by December.

Then in February 2014, she was able to jump on the couch! Now she is bounding up the stairs with ease. She still has a little work to do getting down the stairs, but she is making incredible progress.

Check out the video of her amazing progress below: