Mog, the Forgetful Cat, by Judith Kerr, Harper Books, 1970.
I seriously loved this book. Although I'm wondering why I never heard of it until now. I lived in England from the late 70s to the early 80s, and, although I was a little old for picture books by then, I did read to my younger sister. She would have loved the heck out of this book.
Well, at least I discovered the book in time to give it to my son. He read it last night to his Mog Cat, and I was allowed to listen. Occasionally, he even showed me some of the delightful illustrations. Now I quite agree with him: We need more Mog Books!