Witch's Broom

It is faster in every direction, it keeps working underwater where the saucer bogs down, and it is only as big as you are. That last point matters more than the speed. You can fly through a doorway or down a narrow shaft without dismounting, which is exactly where the Cosmic Car Key gets stuck and sends people reaching for a Rod of Discord. It also arrives earlier, assuming you are running Pumpkin Moons in Expert.

Platforms hammered to the bottom half of their block stop you dead if you try to descend through them and bounce you back up. Ordinary platforms let you through after a short pause. Momentum also carries into the mount, so falling at full speed and then summoning it starts you faster than the broom can accelerate on its own, and the same trick works off a fast-ascending pair of wings.

You can use items while riding, which makes this the building mount. For travel, indefinite flight means wings become optional and you can carry something else instead. For fights most people still swap back, since a fixed mount speed is worse than a wing and boots combination when you need a sudden change of direction.

Expert worlds only. Mourning Wood will not hand it over in Classic, so a Classic playthrough is stuck waiting on the Cosmic Car Key.