Excellent
For the full effect, it really needs to be told verbally and at great, dramatic length. But I will attempt to transcribe it for you ...
[The scene: Lord Vader and Luke Skywalker are fighting a duel.]
Vader: <wheeze> Luuuke, I know what you're getting for Christmas...
Luke: Huh?
[Pad out with light-sabre noises until you feel you are losing your audience.]
Vader: <wheeze> Luuuuuuke, I know what you're getting for Christmas... (<wheeze>)
Luke: Huh??
Vader: I have felt your presents.