So I am looking for a soulmate AU. I believe it was a Bucky/Tony & possibly a Steve/Bucky/Tony fic. The premise is that everyone has a soul animal that ties them to their soulmate. In Bucky's case it was a rather vengeful goose.
I know there are 2 fics like this one. In one I think Steve had a swan for his animal. In the other I cannot remember if Steve had a Goose or not. So I know for certain both should be Bucky/Tony but one might be a Steve/Bucky/Tony or possibly just a Steve/Tony.