Tony adopted Iggy when Iggy was just a 2-month old kitten. For the past ten years, Tony cared for Iggy but when Tony passed away after brain surgery, Iggy is heart broken, looking for Tony everywhere.
Iggy’s behavior shows that cats have feelings too, even if they do act aloof most of the time. To help a cat get over mourning the loss of a favorite human, keep the cat’s routine going with no major changes that could upset the cat.
Also consider placing clothing with the cat’s owner’s smells on them so the cat can still smell his or her favorite person. The smell can comfort the cat and eventually when the cat no longer hangs around those clothes, that can signal that the cat has accepted that the owner is never coming back.