Petshop of Horrors, ???

I should totally know the name of this character... I've never read PoH, but I looked up the character after the con. She had one of my favorite costumes of the entire con! It was very well put together and just plain looked really cool. I felt bad asking what she was from because she looked kind of startled and was like "I'm so-and-so, but I used the colors from the manga." It sounded like she thought I was taking her picture because I liked the character/anime, not the costume...