Like so many others, I just can’t imagine my life without Winnie the Pooh.
I found his Encyclopedia Brittanica entry there.
Also found this from his February 1, 1956 obituary in the [London] Times (behind a paywall):
…it is for his nursery books that his name will be chiefly remembered. Pooh has become an international figure and stands out from countless animals of nursery literature as a classic. There must be in such a classic something that appeals to grown-ups, a quality that makes them wish to introduce the work to their children.