Barsik the 41-pound cat was surrendered by his owner to Animal Care Centers of NYC on April 5 after his family said they were moving and couldn't take him along, according to an Instagram account started to document his progress.
ACC placed the overweight feline with Anjellicle Cats rescue group in Manhattan where one of the volunteers decided she was up for the challenge to foster him and help him shed some pounds.
Barsik is so big that his foster mom said he wouldn't fit in the regular kennels at the rescue. Instead, he got to hang out in the office in a large pen.
His foster mom said cats should usually be around 10 to 15 pounds, or even 20 if they are very large.
Barsik isn't ready to be adopted quite yet, but the public is invited to follow along as he transforms to a healthier cat.