I believe it, 100%.
I just posted about the death of my cat, Stripes. Back in 2010, my cat, Tiger, passed away at the vet's office from an antibiotic resistant infection. He'd somehow gotten a hole in his esophagus and it became infected. I buried him in the garden and the next day, a feral brown tabby showed up and sat on Tiger's grave for 2 days, watching the house. Tiger was an indoor cat so of course he and this cat hadn't known each other. I named him Stripes. While I know that Tiger hadn't come back to me as Stripes, I DO think that Tiger somehow sent him to me as a distraction. I hate to have favorites, but Tiger was a favorite and I always said that when that cat died I was going to lose it. And I did. Coincidence? Perhaps. But if it is it's an awfully odd one.
"Some of you say, "Joy is greater than sorrow" and others say, "Nay, sorrow is the greater." But I say unto you, they are inseparable. Together they come, and when one sits alone with you at your board, remember that the other is asleep upon your bed." Khalil Gibran