Shrek the Halls (2007)
Now, I'm not a huge fan of Shrek at the best of times. I thought the first movie was cute, but already felt dated when I watched it, and I don't remember the second one at all, although I know I saw it. So if you are a huge fan, your mileage may vary.
Overall it's an okay special, I guess, but there is too much idiotic sitcom-style behavior in one half hour for me. What do I mean by sitcom-style? Characters changing their personality or motivation scene-to-scene as demanded by the plot, painfully obvious misunderstandings, useless plot twists that just add time, poor usage of dramatic irony... that sort of thing.
There are about 20 seconds at one point where it gets pretty cute, and then the characters are all idiots for 15 minutes, and then the end is okay. Okay, but still unfunny and plagued with terrible music and Eddie Murphy. Nothing was ever made better by the inclusion of Eddie Murphy.
Although I did like a few of the lines and chuckled a couple times, unless you really like the Shrek series, you can safely skip this one.
If you want to see it, I'm sure you can find it. I refuse to enable you, though.