| The subject of this article has no official name.|
It is a fan-given name as substitute for lack thereof, and should not be considered as part of the Attack on Titan universe.
|Not yet, eh?|
|— The invader anticipates the battles to come|
In his human form, he has a tall, broad, well-toned body with shaggy blond hair and a matching mustache that descends down into his beard. He was seen wearing loose pants with circular glasses and no shirt on.
In his Titan form, he is an extremely unusual specimen, having a distinct, ape-like appearance. Its body structure and facial features are like that of a human's and it walks upright like one as well. It stands at a previously unseen 17 meters in height. Dark fur covers the large majority of its body, with the exception of its face, hands, feet, and torso. Its arms are also elongated, with long fingers and fully-functional thumbs. The proportions of its upper body are similar to those of the Colossal Titan, possessing a massive chest and small head, as well as disproportionately long arms.
The operator is very intelligent and curious. He tries to communicate with Miche Zacharius in order to get information about the omni-directional mobility gear and learn about Miche's language. He has the traits of a leader, giving orders and telling other Titans what to do. While he is talking with Miche, he tells the Titan that is eating him to wait instead of devouring him. If his orders are not followed, he does not hesitate on using brute force, seen when he crushes the head of the Titan that is eating Miche when it disobeys him. The operator also appears very careless of the serious nature of his action, strolling away while Miche screams his last dying breath as he is ripped apart on his order.
The identity and motives of this man are unknown but it is hypothesized by Ymir that the man has an affiliation with the Warriors, indicating he hails from their hometown. She would also note how stunned Reiner and Bertholdt would be upon seeing it, indicating it has a position of authority over them. 
The man who controls the Beast Titan infiltrated Wall Rose and somehow transformed the citizens of Ragako village into Titans. The Beast Titan then led them in an attack within Wall Rose. It is later spotted wandering around by Miche Zacharius, who instantly notes the strangeness of its characteristics, mistaking the Titan with an Abnormal. As Miche's horse races back to him the Beast Titan unexpectedly grabs it. After noticing Miche, the Beast Titan crushes the horse in its hand and 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, the Titan disobeys the Beast and he 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. He also notes how he uses swords indicating that the soldiers of the Walls are aware that the nape is Titans' weakness, and removes Miche's equipment for further inspection. After stealing the equipment he hears Miche's cries of defiance, and allows the surrounding Titans to devour Miche. As Miche screams in horror and pain the Beast Titan is amused to see that he could in fact talk. It then leaves the grounds contemplating the ODM gear ignoring Miche's screams. 
The Beast Titan is later seen again wandering around outside Utgard Castle where several members of the Scout Regiment are trapped by Titans, despite them 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.
While waiting in Shiganshina District, the Beast Titan eventually meets up with Bertholdt Hoover and Reiner Braun, who try to convince him to work with them to free their comrade Annie Leonhart from captivity. When he refuses, Reiner uses his Armored Titan to try to force him to help them, but the Beast Titan swiftly defeats him. As Bertholdt tries to remove Reiner's body from his Titan form, the Beast Titan's operator emerges from his Titan body, telling the two of them that they can rescue Annie after securing the Founding Titan. He then informs them of his plan to wait in Shiganshina to ambush the Scout Regiment in order to capture Eren and the Founding Titan.
This man is able to transform into a 17-meter Titan referred to as the Beast Titan (獣の巨人 Kemono no Kyojin?). He used this form when he transformed the inhabitants of Ragako. It is unknown how he gained his power. He retains his human mind even when transformed, allowing him to do delicate tasks, even speaking.
Some of his abilities are:
- Speech and Titan Control: It is able to fluently speak without issue in its Titan form, casually talking to other Titans and giving them orders which they follow loosely.
- Regeneration: Just like all Titans, the Beast Titan has the ability to regenerate any wound on its body at a tremendous speed.
- Precision: The Beast Titan's throwing ability is second to none, seen when it accurately threw a horse at Miche and again when it lands a direct hit when tossing a boulder at Lynne and Henning from a great distance away atop Wall Rose. It also seems to possess dexterous hands, as it managed to retrieve Miche's vertical maneuvering equipment without damaging him or the gear.
- Miche Zacharius
- Ragako inhabitants
- The Beast Titan shares an English dub voice actor with Shikishima from the Attack on Titan live-action movies.
- He appears to have had limited to no contact with the humans inside the Walls for a long time, as he expresses interest in humanity's omni-directional mobility gear.