Is this the character you mean? http://www.buzzyworld.com/zim/archiv...s/gaz-foot.jpg
If so, I'm sorry, but your costume is not recognizable as her. Gaz wears a dress, and you are missing her most distinctive factor-- her short, square, deep purple hairstyle. The skull appears to be 3-dimensional, so it's more likely a necklace than a print on her dress.