Spine-chiller! Titan Junior High School

Kaidan! Kyojin Chūgakkō (怪談！巨人中学校) is the 8th episode of the 1st season and the 8th episode overall of the Attack on Titan: Junior High anime, produced by Production I.G.

Overview
After the race of the last day, Hange and the other upperclassmen challenge Eren's class to a test of courage. That night they arrive at school, where Hange and Levi explain the rules: they must visit the art, music, and science rooms and write their names on the blackboard. The class splits into two groups and head out, encountering various ghostly apparitions said to be the "Seven Wonders of Attack Junior High"; there is a rumor that anyone who sees all seven will be cursed with misfortune. Finally reaching the gym, they find that the ghosts were in fact a prank orchestrated by the upperclassmen. Erwin Smith, the club's advisor, reveals that one spirit, the woman with black hair whom Christa encountered, was in fact a real ghost.

Trivia

 * When Levi is disguised as the Headless Dribbling Ghost, his uniform heavily resembles Seijūrō Akashi's Rakuzan High basketball uniform from the manga and anime Kuroko no Basuke; the only differences being the word "Rakuzan" replaced by "Shingeki" and the neck lacking the darker tip. This is a nod to the fact that both characters are voiced by in the original Japanese version of the animes.