Just curious if that information is available somewhere, I adopted my pet when I first joined a week ago and I recently made him chibi and he's so great, I'd love to thank the user who put him up for adoption.

I think the only way is to ask in the forums and to hope the previous owner reads it or a friend of them. There is no way to see who owned the pet bevor.

Ask in the forums but there's no guarantee the old owner will respond as they may not wish to take the pet back or are no longer active on site.