The best kind of evil! ...I hope xD
I'm not sure what she's doing this year. I'm kind of hoping she does more suspended things dropping from the ceiling...
Someone copied her balloons in the office this year.

Oh yeah! Another thing was she went with a friend and got a lot of colored sticky notes and gave their bosses' car with an impromptu flame decal with them. I wish I had pictures of all of these...

If you're really out of ideas of what to do you can always gross out your friends by putting black pepper on ice cream. You can't actually taste pepper on ice cream because the combination confuses your chemical sensors and your brain only reads the creaminess of the ice cream rather than the spiciness of the pepper.
... I understand if you don't trust me on that one in an April Fools prank thread... xD