That's right it was the Wheelers from Return to Oz. I loved that movie (still do), but everytime it got to the part where the Wheelers come out I got terrified. Something about their insane laughter and crazy helmets make them pretty unnerving. To this day when I hear that squeak of the wheels I get all tense. I think the best thing about this movie though, is that it's a Disney film. Remember when kids movies where actually kind of terrifying?