What age group is this costume for?
Preschool and Younger
Elementary School
Middle School
High School & Beyond

Estimated time required to make this costume:
Under an hour, depending on if you are dying the sheets.

Difficulty level:
Quick and easy - no sewing required

Items you will need: (Hit your return key to start a new line)
old sheet
dye
Optional: magic marker, glitter, glue

Instructions:
Dye the sheet a spooky color (like a dark blue for a wizard like Merlin). When it is dry, fold it about 1/3 from the top then you could take a marker and mark your place. You could use safety pins to keep the shape, then you can string it or tie it at the ends. To decorate it, you could use marker to draw on it and glue and glitter to give that magic of Halloween.

Other information to consider:
For Merlin, you could dye it dark blue, and before you fold it, take a hot glue gun and glitter and make a border of gold. Then you can fold it and repeat the procedure.