Klaus was a member of the Survey Corps and the team leader of Squad Klaus during the Corps' mission to retake Wall Maria.
Klaus 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.
Klaus seemed to be a very straightforward man. While discussing Grisha Yeager's past, Klaus expressed doubts at Grisha's loyalties, sarcastically noting that Grisha should have helped the Survey Corps more if he truly supported them.
Appearance: Klaus 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.
Personality: Klaus seemed to be a very straightforward man. While discussing Grisha Yeager's past, Klaus expressed doubts at Grisha's loyalties, sarcastically noting that Grisha should have helped the Survey Corps more if he truly supported them.
Klaus in the story: Klaus is seen attending a meeting with Erwin Smith and the rest of the Survey Corps' officers to discuss the recent revelations about Eren's father Grisha Yeager. As the officers depart the meeting in high spirits, Erwin informs them he will leave the teams up to them with Klaus reflecting they should keep the task a secret. Klaus participates in the Survey Corps' mission to retake Wall Maria.
Trivia: The name "Klaus" is a short form of "Nikolaus" which is a German form of the Greek name "Nicholas," meaning "victory for the people."
Source: Attack on Titan Wiki, available under CC BY-SA 3.0.