Duncan Swan is a replacement O.C. pony for Twilight Sparkle in the MLP universe. He is sen to Ponyville to learn about friendship from the locals except Duncan doesn't seem to want to learn about friendship, or even socialize with the others, will he ever be able to get over his hatred of the others. He may seem harsh and evil on the outside, but beneath his outer shell is a heart of gold. They just don't know it yet.