Now see, this video isn't going to intimidate anyone. If you truly want to scare off these dang, dirty trolls, you might want to consider making some changes.
Some animals, like snakes, are brightly colored with stripes to indicate their poisonous nature. https://en.wikipedia.org/wiki/Aposematism
Try wearing something like this:
This is sure to strike fear into the hearts of anyone who would call you "fatty".
If this doesn't work, you can always show your fangs as a last resort.