Metamorphosis is the 50th and final Expert floor in Monkey Ball and Super Monkey Ball, and the 89th Expert stage in Super Monkey Ball Deluxe. It also appears as the 199th Ultimate stage with continues, and the 239th without.
This stage resembles a giant unfolding cube. There is a banana on each side of the cube. Even though it is the final stage in expert, it is generally thought to be one of the easier stages in the last set of Expert stages.
Getting to the goal is not too hard if you know the pattern. Otherwise, it will be quite difficult. Stand on the starting platform until the box opens towards you and lowers a floor. Roll onto the floor in front of you and dash forward. Keep moving onto the other platforms before the floor underneath you moves away. Make sure to get into the goal before the goal platform launches you over the edge.