Bobtail is a young, bright bay stallion. He was slow to forget the gaits and the men, like Angela. He had "the good mouth", meaning he was good with the bit. Some has said that the Seeker favored Bobtail above Centello, the Seeker's horse.
Bobtail is a majestic, bright/rich bay stallion. He is also quite young, about 3/4 years old. He probably has dark eyes, like most other bay horses.
Personality (Contains spoilers)
Not much is shown of his personality in the first book, but in the second book Star Rise, much more is shown. He is shown to be as lively as a colt. He can be very loud, and also stubborn and rude, but he deeply cares about the herd, though showing a slight dislike to Estrella.