I have a soft spot for Twilight: Breaking Dawn Part 2. It's a weird-ass movie in a lot of ways, and it culminates in a super-powered battle that is still better than any I've seen in a superhero movie. One of the things I didn't quite understand in the film is why they had a CGI baby playing the part of Renesmee, the half-human/half-vampire child of Edward and Bella. It turns out that wasn't always the case.
At one point Renesmee was an animatronic doll, but it was so creepy that it earned the nickname Chuckesmee, and director Bill Condon had it banished from the film. Yahoo! has a clip of the terrifying monstronsity in action and it's actually impressive in how scary it is - this would have truly been the most horrifying thing in a series that sort of uses horror tropes but is never actually scary. You have to really respect poor Nikki Reed in the clip above as she attempts to act opposite that thing.
This is one of those rare instances where a practical effect manifestly does not work - at least not in the context of Twilight. If this had been a straight horror movie, Chuckesmee would be a legend already.