"People fell in love with him. Is it his face? Is it his demeanor? Is it his size? Nobody knows really what it is," said the cat's new owner, who asked to be identified as Sarah B.
Sarah and her boyfriend Chris, both veterans, are the lucky couple who get to call Mr. B theirs.
"Instantly I knew, we both loved him when we saw his photo, like much of the world did," she said.
Sarah, a grad student at Temple University, says she was in the middle of class when she got the call. She rushed to the shelter, where she cried tears of joy when she met her new furball of love.
Today, Mr. B is comfortable and living his best life in Point Breeze. He has four fur brothers and sisters.
"So we have one who's 15, one who's 14, and the other two are 4. They're brothers. And then Mr. B is 2, so he's now the big baby of the family," Sarah said.
Sarah and Chris, who are familiar to many local shelters because of their rescue efforts, also use their extra bathroom to foster kittens until they find them forever homes.
"We rescued one cat in the beginning," said Sarah. "It kind of just led to us realizing that this is something that we really love and care deeply about."
Mr. B, who did several cameos when he was in search of a home, now keeps up his social appearance through Instagram. There the world can keep up with his favorite cat-ivities. One of his favorite pastimes is getting a toothbrush grooming from his mom.
A post shared by BeeJay - aka Mr. B! -- (@chonkymrb) on Nov 2, 2019 at 4:59am PDT
Sarah says their "corner of the internet" is one of the most positive and compassionate places in the world.
She and Chris also use his platform to find homes for other shelter cats and to raise awareness of animal care.
"It's really easy us for to take Mr. B's account and say, 'Hey, here's this really cute cat,'" she said. "And the difference with having him in our home -- instead of in a refuge or shelter environment -- is that you can clearly see how they interact with us. And someone who is interested in adopting a cat can imagine them in their home. They see us love on them and how sweet they are, and they get to really learn their personalities. But there is some sort of magic and charm around Mr. B."
Sarah says it's the little things that count.
"I tell Mr. B's friends on Instagram: It starts really slowly. It's one can of cat food that you set out for a stray cat. It's one animal that you take in and put in you spare bathroom for a few weeks until it finds a home," she said.
And since they recognize the happiness that Mr. B brings to the world, it makes them happy to share his journey.
"Every little thing you do collectively among all of us adds up to really, really big things, and we feel very deeply about that. It doesn't matter how big the gesture. It's just that you do that one little thing. It does wonders when you add it all up -- across this city and across the world," she said.
Sarah says they're working to get Mr. B down to a healthy weight, which the vet says is around 18 pounds.