On the way to Helm's Deep in The Two Towers, the people of Rohan were ambushed by orcs riding Wargs - giant wolf-like creatures. Frankly, to us, they look more like a wolf crossed with a hyena, but maybe we're alone on that. In any case, it wasn't really the look of the Wargs that bothered us, it was their movement. In The Lord of the Rings, they just seemed stiff. Seeing one fall down dead was like watching a model topple over. Given how good the CGI in the movies was, it was jarring to see a moment when it wasn't up to snuff. Thankfully, this has been improved in The Hobbit series, and the Wargs move much more naturally. There is also considerably more variation between individual Wargs, thanks no doubt in part to improvements in CGI tech over the past decade.