The Battle of the Labyrinth
Grover Underwood: A satyr and Percy's best friend. His life's ambition is to find Pan, the lost God of the Wild. Grover, Tyson, Percy, Annabeth, Nico and Rachel find Pan inside a crystal cavern along with some extinct animals. He gave them words of wisdom, and then died. When he died, his essence entered all of the characters' mouths, meaning a piece of the wild remained in their hearts. He gave Grover the famous battle cry, panic, which Grover used to scare off the intruders in Camp Half-Blood. The god Pan is named after panic because in the Titan war he let out a horrible cry that drove all the monsters back to where they came from.