Grover Underwood, a satyr, is Percy's best friend. Grover is described as having curly brown hair, brown eyes, pimply skin, a wispy beard, and brown goat-legs (which he disguises with fake feet when necessary). His horns grow larger as the series progresses, and he must take increasingly careful measures to hide them while posing as human. He is a vegetarian. Grover is a very sensitive person, concerned particularly for the safety of nature and nature spirits -- and like all satyrs, he can sense the emotions of others around him and smell monsters and demigods. As the series progresses, his concern for his friends and pursuit of his goals lead him to take on leadership roles and become more sure of himself. In The Battle of the Labyrinth, he begins a relationship with the wood nymph Juniper.