Get transformed by the Hallowed Wands listed below.
This achievement is obtained once you are turned into all of the different costumes by the various wands. The best way to do so is to group with other players and trade or buy wand transformations.
The wands can be obtained from the following:
This achievement can be earned outside of the duration of the world event. Just have to find someone who has a wand of the transformation(s) you need.