At the end of Attack on Titan Season 2, the theory arose amongst the Scouts that titans were transformed humans, and this would later be confirmed in Season 3. Throughout the first two seasons there were clues to this, especially when Eren first transformed into the Attack Titan and when it was revealed Annie was another shifter; however, the biggest clue to this was with Ymir, a character who was a mystery from day one. While other protagonists got some form of backstory, Ymir's was always kept in the dark, and for good reason.
It wasn't until Season 2, Episode 4, "Soldier," that it was revealed she was another shifter, and shortly after, in Episode 5, "Historia," the audience learned she obtained this power by eating one of Bertholdt and Reiner's comrades, which turned her from a mindless titan into the shifter known as the Jaw Titan, who was originally sent alongside the Titan Trio to destroy the walls and obtain the Founding Titan. The titan would later return to Marley, with Porco inheriting its abilities after eating Ymir. Like all shifters, the Jaw Titan has a unique anatomy compared to mindless titans, which gives it an advantage.
The Jaw Titan Is the Smallest Titan Shifter
Upon first glance, the most notable thing about this shifter is its size. Compared to all the other shifters introduced in the anime -- the Attack Titan, the Founding Titan, the Colossal Titan, the Armored Titan, the Beast Titan, the Cart Titan, the War Hammer Titan and the Female Titan -- the Jaw Titan is the smallest, and it is even smaller than most mindless titans.
This comes with advantages, which will be addressed later on, and disadvantages, such as being overpowered by larger titans, as seen in "Historia" when the mindless titans finally outnumber Ymir, toss her like a rag doll and devour pieces of her. Meanwhile, Eren's titan was able to grab Porco's Jaw Titan by the neck and nearly kill him once he was in his grasp.
The Jaw Titan Is Faster Than Humans, Mindless Titans and Most Shifters
Unlike the Colossal Titan or Rod Reiss' Titan, who both move ungodly slow due to their massive sizes, the Jaw Titan, thanks to its petite build, is one of the fastest shifters. Throughout the second half of Season 2, audiences see Ymir easily catch up to Reiner's Armored Titan and out run the scouts with their ODM gear.
Even before the other characters know about the Jaw Titan, Historia notices that Ymir is hiding something when she makes it down the mountain with Daz without any climbing gear and in record time. This should've taken an average person hours, and even for a titan it would've taken a while, but Ymir's Jaw Titan speeds down fast enough to save Daz from hypothermia. Porco's titan similarly has remarkable speed, saving Reiner from an anti-titan canon in quick time and shielding Gabi and Falco from a rain of bullets.
The Jaw Titan Can Out Maneuver the Scouts
Along with heightened agility, the Jaw Titan has more flexibility and dexterity than any other shifters. While the Armored Titan, Female Titan and Attack Titan have all displayed fighting capabilities, they do not have the same grace as the Jaw Titan, who can easily maneuver out of tight situations while also landing devastating blows. At Castle Utgard, fans see how effortlessly Ymir can scale the tower, leap from titan to titan and hurl pieces of brick at her opponents, mimicking the grace of dancer or spider.
Meanwhile, in the Giant Forest, Ymir swings like a monkey from branch to branch and preforms flips like an acrobat, which allows her to escape the Scouts. As for Porco's Jaw Titan, he can hop from the buildings in Liberio, almost getting the jump on Eren. He also uses this dexterity during the war to jump from canon to canon, destroying them before they can obliterate any of the other Warriors.
The Jaw Titan's Claws Are Stronger Than the Scouts' Blades
What helps with the Jaw Titan's acrobatics is its sharpened claws. While other shifters, like the Female Titan, have had to use their crystal abilities to make claws, the Jaw Titan naturally has a set of nails that can penetrate the hardest surfaces. With Castle Utgard, Ymir is able to hold onto a smooth surface thanks to her claws, and she is able pierce titan flesh with them, which is impressive when considering the fact that the Scouts had to develop specialized blades to achieve the same feat.
Similarly in the Giant Forest, Ymir can hang onto trees like the Scouts because her claws anchor her like their ODM gear does. Meanwhile, Porco's claws scratch the crystal Lady Tybur is in, a crystal like Annie Leonhart's, which was considered to be unbreakable by the Scouts.
The Jaw Titan's Bite Is the Strongest Out of All the Warriors
The biggest advantage of the Jaw Titan is its jaw, which is the strongest of the titan shifters. Where most shifters and mindless titans have teeth that resemble their human set, the Jaw Titan develops a mouth full of razor sharp fangs. Along with being sharp enough to easily penetrate the nape of titan's neck, this jaw can unhinge itself without the need of damaging the mouth, as the Female Titan had to do.
This makes the Jaw Titan's anatomy similar to that of a snake, as well as an alligator given the immense amount of strength the Jaw Titan can exert in a single bite, which makes this shifter incredibly dangerous. For instance, Porco is able to take off Eren's hand with a single bite, but perhaps the most impressive display of this is when Porco's Jaw Titan is used like a nutcracker to shatter Lady Tybur's crystal, brutally killing her. Not even Eren's titan is able to achieve a bite like this, damaging his mouth when he attempted to do the same.
