I posted about this already in "I'm Looking For", but nobody could help me. I felt I could have a better chance here.

I read this a LONG time ago, so I don't remember much about it. I apologize in advance 😅

I know the MC had a dog that passed away, and so he picked up a white cat that reminded him of his white dog. But, I think the cat was actually tiger?? And he turns into a human man. But, I think there was a twist where the dog wasn't actually a dog, it was the cat?? And MC's memories had been altered?

To the best of my knowledge, the tiger's human form is tan, and I'm pretty sure MC names him Beom. The MC also has a friend, from school, I think, that starts to get worried about him as the story goes on. If this rings any bells for anyone, I'd really appreciate it! I really want to find this one, it's driving me crazy!

This doesn't really match but it it was the first thing i thought of. more related about being tan and the friend. . Making a Child with a Beast Biting the Tiger

second just came to mind as typing. I feel like I might have read this but like you said, it probably would have been so long ago. 😅

I would check this tag if you haven't and hope its tagged right. https://www.mangaupdates.com/series?category=Animal+Transformed+into+Human

Neither of those are it, but I'll definitely browse the tag! Good call lol thanks for trying 😁

So I kinda remember this story as well but not the name. MC has a little dog he loved and would always rush home for. Dog dies and makes a deal with a God to come back to heart broken MC. In human form, MC refers to the human version of the cat as Mr. Cat. One of MC friends is not a good person and Mr. Cat remembers him hurting the MC and lashes out at the friend and transforms showing his ears and claws. The friend then tries to get MC away from Mr. Cat calling him a monster. That was one of the last chaps I remember. I think I found it Cat in a Cardboard Box https://www.mangaupdates.com/series/4wxuuac/cat-in-a-cardboard-box