Certainly sounds like it could have been Carl! And what a comforting thought that is to all of you who knew him...that he is watching over you and your bunnies, still present in some form.
I never used to believe in the after life, or angels, or any of that. Some strange things did happen in our house when I was a child, but they scared me so much that I didn't want to acknowledge it. But in the past few years my entire life was turned upside down...and I discovered that angels do exist (as do ghosts, spirit guides, etc.). I even created a website that explains how I *met* an angel three years ago...the archangel Gabriel...one evening. That was the beginning of my no longer doubting their existence.
One thing that occured when I was a child happened whenI was around 11 or so, I was awakened from my sleep one night to the sound of my bedroom door slowly opening. My head was buried under the covers (I used to be very afraid of the dark), and I remember lying there shaking, far too afraid to peek out and look. Then I heard footsteps approaching the bed...it was someone wearing shoes, not difficult to hear because I had a hardwood floor. By that time I was so terrified that I couldn't move even if I wanted to, and I remained frozen in terror for what felt an eternity. I know that I eventually did fall back to sleep, maybe an hour or so later, not hearing any more footsteps, but my sleep was a restless one. When I woke up in the morning it was the first thing I recalled, and I wondered if I had actually dreamt it. But then, as I sat up and swung my feet towards the floor, I froze...the bottom drawer of the cedar chest that was next to my bed had been pulled open, and the contents...letters from my brother who was training in the army down in the United States...were strewn everywhere. Of course no one else in the house believed me when I told them about it, and eventually I learned to not talk about it, lest I be teased. But I do believe now that this 'entity' was my mother, who had passed away the year before. My brother was enlisted in the US army right when the Vietnam war was raging, and I think some part of her was watching over him. She was drawn to that cedar chest, which had been hers when she was still with us, and to the letters that my brother had written to the family while he was in North Carolina.
Anyway, I do believe that what you saw, JimD, was certainly a presence of some kind, and it wouldn't surprise me in the least if it was Buck Jones himself. I wonder if he is visiting all of his friends' and aquaintances' homes, checking in on the rabbits and the people he loved.