Attack on Titan Season 1 Episode 17

Female Titan: The 57th Exterior Scouting Mission, Part 1

Subbed

As the Scout Regiment begins its push toward Shiganshina, they encounter an intelligent Female Titan unlike any they’ve seen before. When Armin hypothesizes that it’s really a human that’s been turned into a Titan, he, Jean, and Reiner attempt to stop it.