Phil

Phil (フィル) is a member of the Garrison.

Clash of the Titans arc
Phil was one of the many soldiers dispatched beyond the walls to rescue the kidnapped Eren Yeager and Ymir from the traitors Reiner Braun and Bertolt Hoover. When the soldiers were attacked by Titans, Hannes ordered Phil to lead their horses away from the Titans.

Trivia

 * Although it is never specified what branch of the Military Phil belongs to, the fact that he takes his orders from Hannes means he is likely a member of the Garrison.