I lost my son 7 years ago. We have an image if a frog on his headstone since frogs reminded us of him (he always had a stuffed had a frog). About a month after we lost him, when we went to visit, there was a live frog sitting in his headstone. It stayed the entire time we were there, not scared off by the kids. I know it was my son.
My husband passed a few years ago, he comes as a Hawk. He always said if he was an animal it would be a Hawk. Now he gets to be when he wants to visit