One of the most outrageously unexpected moments in The Lego Movie was the appearance of Milhouse van Houten in the Master Builder meeting scene, and though he doesn't speak a single word, the sheer randomness of it was enough to get plenty of laughter out of me. If they wanted to expand the joke, it would be pretty awesome to see Bart Simpson himself make an appearance, skateboarding through Bricksburg and maybe pranking one of the main characters. Too much Bart would probably be a mistake and make the film teeter over the edge of feeling like a massive corporate sponsorship seminar, but a little of the 'Lil B***ard could go a long way. Or failing that, what about Homer turning out to be a Master Builder? The sheer absurdity of that would be good for a few laughs.