A stray cat that sported a permanently sad look has been transformed a year after he was adopted.

Bruce Willis, the orange tabby, had scars from fights with other cats and problems with his immune system when he was taken into Animal Humane Society in Minnesota, US.

His healed eye was a little droopy, his one ear was a little cockeyed, and his scars left his fur looking a little bedraggled.

But luckily he was rescued by cat lover Sandra, who persuaded her landlord to make an exemption for the apartment's no-pet policy.

The six-year-old cat was taken to Sandra's home last August and started a new life as a loving pet.

Bruce Willis was living on the street before he was taken into an animal shelter
Bruce Willis was living on the street before he was taken into an animal shelter

Video shared by Sandra on her TikTok @mrwillisthecat documents Bruce's changes in the past year after she explained he was the "saddest cat" she had ever seen.

In the montage clip, the moggie enjoys a little rub on his belly and likes to sleep by Sandra's feet.

As Bruce slowly adapts to the new place, he becomes more active.

In one clip, he is seen dragging a catnip toy across the room and going out for a walk in the snow in his military green vest.

But he found love from his new owner Sandra, and has completely transformed after moving into a new home
But he found love from his new owner Sandra, and has completely transformed after moving into a new home

Sandra writes in the post: "It's been a year since I adopted him and he is now the happiest cat I know."

Bruce's orange fur is no longer rough but looks radiant in the sun. His adorable eyes are round and big.

The clip has touched millions of hearts on social media and viewers are glad to see Bruce's transformation.

One wrote: "You literally can see the life come back in his eyes at the end!"

Bruce now looks right at home
Bruce now looks right at home

"He looks so different, omg. Thank you for adopting him," a second added.

A third said: "He's such a little bear. You two are so lucky to have each other."

It comes after another video surfaced of an adorably goofy cat having the time of his life by getting a head rub.

Meanwhile, a kind-hearted dog was filmed handing a stray cat its own food after spotting it in its garden.