BeepBop was 2 years old when he ran way from his Brooklyn Heights home in June 2011.
His owner Cathy Sheehan was moving out of her Columbia Place apartment when BeeBop slipped out of the window four years ago. To help her search, Sheehan started a Facebook page called "Where is BeeBop?" a few days after he went missing.
Today, the page has 4,738 likes. Sheehan continues to update it regularly with photographs and articles about missing pets and is offering a $2,000 reward, no questions asked, for the tuxedo cat's safe return.
"I'm trying to keep my hope alive and my page alive," she told DNAinfo New York.
People also post their own stories of lost animals, pleas to help find them and adoption notices for dogs and cats.
Sheehan, who is now in her 50s, had lived in Brooklyn Heights for more than 20 years before moving to Maine just a few days after BeeBop ran away. She said she believes the cat escaped because he was scared of the movers.
Although she couldn't stay in Brooklyn to look for BeeBop, a network of friends and neighbors in the area continued the search by posting fliers and sharing the cat's picture, she said.
Sheehan got her hopes up in early July 2011 when she was told BeeBop had been found in the basement of a local community center and theater.
She returned to Brooklyn over the Fourth of July weekend to pick him up but by the time she arrived, the door to the basement had been opened and the kitty had run out again, she said.
Sheehan, who works as a legal assistant and has two other cats, still gets calls and emails about BeeBop-like cats but none have led to her pet's return.
Still, she holds out hope that he will come back to her. No one, she said, has ever called to report that BeeBop is dead.
And while she bears no hard feelings toward anyone who might have found and kept her cat, she will continue posting on her Facebook page until BeeBop comes home.
"Some people don't understand how I can keep looking," she said. "I just really want my cat. My heart is broken."