Pegasus

A pegasus is a horse with wings. They are described by Sophie Foster in Book 2: Exile to be small and husky, with dark blue spots and midnight blue manes.

Physical Appearence
According to book 2, pegasi are "smaller and huskier [than Silveny], with deep blue spots and midnight blue manes."

Trivia

 * It is possible that pegasi and unicorns bred to create alicorns.
 * Sophie learned of a pegasus's appearence from books rather than experience with them, hinting that there may not be any at Havenfield.