Voiced by Andy Serkis, Gollum is a twisted and ancient creature, a living example of what happens when someone allows himself too much exposure to the all-powerful One Ring. The character is as deeply fleshed out and real as any portrayed by live actors.
Integral to the story, Gollum is not some animated footnote or one note gag real. Ironically, the newest and most important addition to the Lord of the Rings mythos this time is also another cgi creation. The warmth of the character itself, and the brilliant way in which he interacts with live actors easily endears and captivates the audience, as does the Ent subplot, which sees a gentle and mild race driven to an unthinkable war. But even that is infinitely preferable to the plasticy cgi creations usually present in other modern effects heavy innovations. Often, Treebeard looks almost like a stop-motion character who wandered over from the set of The Nightmare Before Christmas. In close-ups it becomes more difficult for the WETA effects crew to maintain that same level of quality. He and his brethren fit so perfectly into their environment that it’s easy to at last see what Tolkien had in mind when he first imagined Ents on paper so many years ago. In wide shots, he’s rendered beautifully with his massive scope and size nicely contrasted with the even more massive landscape around him. Voiced by John Rhys-Davies, who also plays the spectacularly used dwarf Gimli in the film, Treebeard is a splendid creation. Walking tallest among these is Treebeard, chief of the Ents, a race of forest striding tree-shepherds who look nearly as treeish as the foliage they herd.
In fact, despite Jackson’s propensity for using models rather than not-yet-realistic cgi, Towers actually features not one, but several completely cgi characters.