Gatrie is a member of the Greil Mercenaries that appears in Fire Emblem: Path of Radiance and Fire Emblem: Radiant Dawn. He's polite and can't resist aiding a woman in need, though despite his attitude, he has difficulty in courting ladies. Among the mercenaries, his closest friend is Shinon.
In Path of Radiance, Gatrie, like Shinon, chooses to leave the Greil Mercenaries after Ike becomes the company's new leader following Greil's death. He eventually takes on work as a bodyguard for Astrid, a noble of Begnion. By chance, he and Astrid are on board a ship under attack when a ship carrying the Greil Mercenaries comes to their aid. Following the battle, Gatrie has a change of heart and rejoins the mercenaries.