This one is a bit more justifiable than some of the other ones. It answers a couple of the key questions about Santa. First, how can he visit every house in the world in one night? He's a time traveler. How can he fit billions of gifts into his sleigh? The sleigh is his TARDIS. How does he fit down chimneys? I'm gonna go with some sort of sonic technology. Flying reindeer? Part of the TARDIS (his chameleon circuit is pretty sophisticated). Okay, I need to stop watching Doctor Who and reading the WMG pages.