Tristan

I knew pretty much from the start that Terence would have some kind of sibling, and I always had a hunch it would be a brother. I considered giving him a sister, too, but changed my mind. 

Tristan is the oldest and largest of the two. He's as handsome as anything, and also as vain as anything. While just about every unicorn possesses some vanity (never call a unicorn a horse to his or her face!), Tristan is notably narcissistic. He gives himself ridiculous airs and goes out of his way to show he's the most superior, especially to his brother.

While he comes off as silly, superficial, and a bit of an idiot, he does have a good heart. In fact, you'd be surprised at what you'd find behind his mask. You wouldn't think the stallion ever had any self-esteem issues. But the truth is, he acts like he is so important just to feel important at all. He's jealous of Terence for a host of reasons, possibly the biggest reason being he believed Terence was their mother's favorite.

For all that, Tristan loves Terence, even if he doesn't always know how to express it, and will do anything to keep his brother safe. That's the beauty of their relationship: no matter how much they aggravate and infuriate each other (and trust me, they get into plenty of squabbles), whenever one is in trouble, the other will always be the first to do something about it.