|That monkey Beast Titan is what caused this recent fiasco. It made Titans rise up from within the Wall. I wonder if he was trying to assess our strength.|
|— Ymir speculates about the purpose of the Beast Titan's arrival|
The Beast Titan is able to exercise some control over mindless Titans. Through vocal commands, the Beast Titan is able to direct the actions of mindless Titans and can command them to refrain from eating humans and stay in place if necessary. Titans under the Beast Titan's control are even able to function using only moonlight without falling into fatigue. However, this ability is evidently imperfect in comparison to the Coordinate. Titans under the control of the Beast Titan either seem to be capable of ignoring orders or occasionally do not receive or comprehend orders given. Furthermore, Titans under the Beast Titan's control cannot act upon the unspoken will of the Beast's user, unlike the Coordinate, and must be given some sort of direct verbal signal before taking action.
When Titans mysteriously appear within Wall Rose the Beast Titan is among them and is encountered by Miche Zacharius, who instantly notes the strangeness of its characteristics, mistaking the Titan with a regular Abnormal. As Miche's horse races back to him the Beast Titan unexpectedly grabs it. After noticing Miche the Beast Titan launches it at him preventing his escape and throwing him from the roof he was on. After Miche falls to the mouth of a Titan, the Beast Titan orders the other Titans to withhold on eating him so that it can question Miche about the omni-directional mobility gear.
However, a Titan disobeys the Beast and it crushes its head to release Miche. The Beast Titan then proceeds to interrogate Miche, but as he neglects to respond out of shock, it theorizes that they do in fact speak the same language, but Miche is simply too frightened. After stealing the equipment, it allows the surrounding Titans to devour Miche. Miche screams in horror and pain while the Beast Titan is amused to see that he could in fact talk. It then leaves the grounds contemplating the ODM gear.
The Beast Titan is later seen again wandering around outside Utgard Castle where several members of the Scout Regiment are trapped by Titans, despite Titans usually being inactive at night. It then climbs up Wall Rose and watches the Titans surrounding the tower from a distance. After the Scouts kill most of the larger Titans, the Beast Titan begins throwing large stones at the tower, killing Lynne and Henning along with their remaining horses. Shortly afterward, twice as many Titans begin to advance while the Beast Titan roars at them from atop Wall Rose. Nanaba notices the unusually strategic method in their attacks, indicating that the Beast Titan is controlling the other Titans' actions. As the Titans swarm Utgard, the Beast Titan descends the other side of Wall Rose.
The next day, while Reiner and Bertholdt are holding Eren and Ymir captive, Ymir notes how stunned the two had appeared when they first saw the Beast Titan at Utgard as if they knew what it was. She also theorizes that it is a key factor in their return to their hometown. Shortly afterward, the Beast Titan stops in Shiganshina District, and the operator emerges from its nape, seemingly anticipating something to come.
- The Beast Titan shares an English dub voice actor with Shikishima from the Attack on Titan live-action movies.
- The Beast Titan's appearance resembles several cryptids, such as "Bigfoot," the Yeti, and Yowie.