The Peering Titan (覗き込む巨人 Nozokikomu Kyojin?) was a former Eldian Restorationist who was captured by the Marleyan Public Security Authorities and turned into a Titan for the crime of treason.
In human form, this restorationist was of average build and height. He had shaggy brown hair and large brown eyes. His face had very pronounced, tense features and lines; his eyes and eyebrows were almost always tensed and squinting slightly. His resting face usually made his teeth visible. He was only ever seen wearing black pants and shoes, a white button up shirt, and sometimes a dark colored blazer.
The Peering Titan was a 3-4m class Titan and had a disproportionately big head and shoulder-length, messy, brown hair with brown eyes. Its body was relatively toned, and it always had an angered expression on its face. It also notably retained all of its original facial features and therefore heavily resembled its human self.
In his human days, the Peering Titan was a member of the Eldia Restorationists. He was present when Grisha Yeager found out about his sister's real cause of death at the hands of Marleyan soldiers and he cheered Grisha on as he went through the initiation ceremony of carving an "X" into their skin. For several years, he worked with the restorationists on their discovery of history and plan to bring Eldians back into power. He was present when Dina Fritz appeared before them as an ally sent by The Owl, their mole in the Public Security Authorities. After learning of the Eldia's true history and the Great Titan War, he cheered with his comrades when they agreed to take back the First King's power and give it to Dina, the last of the royal family.
When the Marleyan government decided to select Eldian children as Warriors to take down the King on Paradis Island, he rallied with his comrades to decide their plan. They then discovered from The Owl that the Marleyan government only wanted to go to war so they could steal the fossil fuel below the island. Grisha offered his son, Zeke Yeager, as a volunteer and mole for their organization. However, two years later all the restorationists were turned in by Zeke and sentenced to go to Utopia and spend the rest of their lives as Pure Titans that ate their own kind.The Restorationists were all then taken on a steamboat to Paradis Island and forced to kneel on the edge of a large Wall. First, one of the restorationists was kicked off the Wall as a human and told to make a run for the Walls. After this, all the Restorationists, except the human Peering Titan, Dina, and Grisha, were injected with Titan serum and kicked over the Wall. Moments later, they all turned into Titans and ran after Grice. After Dina was transformed, Sergeant Major Gross then decided that he would turn the last restorationist into a small Titan that would eat Grisha. After this, the human Peering Titan was injected with a Titan serum and pushed over the Wall, turning into a Titan moments later.
Before Gross could push Grisha over the Wall, Kruger pushed the sergeant off the edge. He hit the ground and rolled on the sand-dune and found himself face to face with the Peering Titan. The Peering Titan picked Gross up and took a bite out of his face, ripping a portion of his skin and muscles off before he continued to devour him.
During the battle for Trost District, a Bigmouth Titan happens to catch its arm on Mina Carolina's vertical maneuvering equipment grapple wire as she is trying to attack it, bringing her crashing against the Wall and then down to the ground, knocking her into a daze. The Peering Titan spots her just before she gathers herself and then goes on to pick her up and bite most of her head off as she struggles, killing her as other trainees die around them.
Peering Titan is seen once more afterward, having made its way with other smaller Titans into the equipment depot of the military headquarters in Trost. As part of Armin Arlert's plan to clear out the Titans from the depot, Sasha Blouse attacks it, but fails to land a killing blow. As the Titan approaches Sasha, Mikasa Ackerman comes to her rescue, killing the Titan.