The dirty, garbage-filled fur shaved from Sinbad in December weighed almost as much as he did

It’s amazing what a haircut can do.

Case in point, Sinbad the cat, who was found in the basement of an elderly man’s home in December, carrying 5 lbs. of filthy, matted fur.

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The Anti-Cruelty Society‘s humane investigation team received a phone call from a municipal worker about the feline who was living — if you can call it that — in a basement on the south side of Chicago, a shelter spokeswoman tells PEOPLE.

“Our humane investigation team went to the location and spoke with the owner of the cat,” says PR manager Colette Bradley. “He was an elderly man whose mental health was failing and he couldn’t care for the cat. Our humane investigators asked him if he would be willing to relinquish the cat into our care and he agreed. We brought him in to our facility and began to shave the 5 lbs. of matted hair off of him. It ended up taking two shaves.”

Just as startling as the cat’s physical transformation was the personality that emerged once the cat was cleaned up.

“As soon as that hair started coming off and he could walk, he started rubbing up against the people in the room,” Bradley tells PEOPLE. “He was so affectionate and was looking for love in return. We were all shocked by how friendly he was considering he had such limited human interaction in his life prior to being rescued.”

With the garbage-filled fur removed from his body, the cat weighed in at 6.63 lbs. and could definitely stand to gain more. Thanks to a new diet, Sinbad now weighs 7.25 lbs., the shelter says, and continues to make huge strides in the new year.

“He started using the litter box quickly which was fantastic since we weren’t sure he had ever had one or knew how to use one,” Bradley says. “At first, his back legs were atrophied and he was having a hard time walking around without falling, but within a few days he had built up the muscles in his legs and was able to jump up on furniture.”

Sinbad was fostered in-house at the Anti-Cruelty Society for a few days until an employee named Elliott Serrano volunteered to take him home for Christmas — and that’s when a foster became forever.

“They both decided pretty quickly that he was there to stay,” says Bradley. “His hair is growing in really well now and is so soft! He loves to lay on Elliott’s chest and purr. He’s very happy in his new home and is really thriving!”

Sinbad now has an Instagram page that tracks his style adventures — an outfit with purple sequins is not to be missed — and snuggly naps.