A very specific type of superpower. The character has the ability to change their size. Usually, this starts off one way, such as only being able to shrink or grow. Eventually, this starts to seem a little lame (unless the change comes with added Super Strength, or other Required Secondary Powers in order to offset that pesky Square-Cube Law), and they probably end up being able to do both with an upgrade of some sort, or a Hand Wave about training. Compare Make My Monster Grow, where a character makes a monster grow to great heights. Examples of Sizeshifter include: