This AMV was done by YouTube user BevinKB back in 2007 and, while the video quality may be somewhat lacking, the syncing and timing is great. Not to mention believable: I certainly wouldn't put it past a self-absorbed villain like Presto Change-O to sing such a narcissistic song about himself.
(Okay, okay! I'll post the original Lazytown video, too, so you can compare. Gotta admit the villain is actually a bit amusing to watch while performing this song...)
(What's that? You want to hear the song in its original Icelandic version, too? Fine! Okay! But just because it's so damn catchy. I can't believe I just said that about a Lazytown song.)
UPDATE (February 18, 2013): The original YouTube video I had embedded for the English Master of Disguise scene from Lazytown has long since vanished. I probably wouldn't have bothered to fix this if it hadn't been for the fact that the song is up on Lazytown's official YouTube channel. But since it is, I thought I might as well...