Wizards of Waverly Place (2007)

Season 4: Episode 5

Alex joins Justin's wizard class to try to move up in the competition. Max joins a sophisticated wizard society. They suggest he move the wizard competition up and he moves it to a few days away. Max quits the society because he finds out that they are taking advantage of him. Alex and Justin transform into Max in an attempt to change the date of the family wizard competition back to it's original date and succeed. In the end of the episode they accidentally turn Max indefinitely into a little girl.