My friend Henry Gee has a couple of typically well-written and imaginative posts on his blog End of the Pier Show: in On Inspiration, he describes inspiration as being nonlinear, multiply connected and highly recursive.
To be specific, what inspired the creation of the Ents? At first glance, the venerable Shepherds of the Trees that figure so memorably in The Lord of the Rings must count among Tolkien’s more original creations. But how original is ‘original’? Can we trace the things that influenced Tolkien’s seemingly unique fusion of people and trees?
Henry goes on to say that "Ent" is the old English for "giant", and that it is clear from Tolkien's drafts that the author wanted to write about a giant called Treebeard, but it was only when he actually put pen to paper that the character became a tree. Do read Henry's post, it is brilliant.
Earlier in his post, Henry hints that he'd not be averse to a copy of The Children of Hurin for his upcoming birthday. Well, the right fairies were reading his blog, because he was given the book. Here's his review.