Dirk was a man of average height and build, with short blond hair. When not wearing the standard Survey Corps uniform, his attire consisted of a button-up shirt and dark pants.
Dirk participates in the Survey Corps' mission to retake Wall Maria, and after the emergence of the Beast Titan and his forces, Dirk's squad is ordered by Erwin to regroup with Squads Marlene and Klaus to guard the Corps' horses. He and his fellow soldiers fight off nearby Titans to protect the recruits in Dirk's squad while they move the Corps' horses to a safe place. During the fighting, however, Dirk and his fellow soldiers are killed by the Beast Titan, who starts throwing crushed boulders at them, cutting them all to pieces.