|◄ Preceded by|| Rod Reiss|
|Followed by ►|
| Frieda Reiss|
| Historia Reiss|
|There is meaning in every catastrophe. Whether humanity is fated to die, or survive...that decision is in God's hands. My mission is to summon God back into this world and offer my prayers to her.|
|— Rod urges Historia to take the Founding Titan|
Rod, like his daughter, was a rather short person. Though, unlike his daughter, he was a slightly overweight man, with a round face, short, jagged black hair and a thin black mustache. He was typically seen wearing the clothes of a wealthy man, featuring a white button-front shirt with a black pullover vest, loose black pants and black dress shoes. However, when conducting the Titan rituals, he wore a white shirt and pants with a long coat, as did the other Reiss males during family meetings.
In this form, Rod was an abnormal Titan. His appearance as a Titan retained practically nothing of his human form, except for still being male-like as most Titans are. He grew to the point of becoming the largest Titan ever known, reaching 120 m in total (40 m at the withers), twice as large as the Colossus Titan, which is 60 meters in height.
However, his body was quite disproportionate, having a large torso with a small head, and very thin limbs for his size, thus being unable to stand up and needing to crawl on all fours. He was also notably skeletal, with most of his bones clearly visible and lacking in muscles. He lacked a face due to the friction against the ground as it destroyed the front half of his head due to his constant dragging as he moved, exposing even his brains. However, if he were to remain off the ground and not dragging his head, he would regenerate a full face in time. His ribs covered only the sides of his body, and his frontal area lacked skin and muscles also due to him dragging his body as he moved which also exposed his internal organs when he sat up.
Like the Colossus Titan, his enormous size made him move slowly and generate lots of heat, always being covered by clouds of steam. The heat he produced was so high that it was impossible to go near him without getting burned, as the trees near him burst into flames instantly.
Rod often appeared to have a calm, yet slightly worried demeanor. He spoke with great certainty and intelligence about the events of his daughter, Frieda Reiss, and his brother Uri Reiss, when they obtained and lost the Founding Titan. Rod maintained a level head throughout most of his time with Historia, Eren Yeager, and Kenny Ackerman. He even gathered his composure after Kenny grabbed him and began shoving a knife down his throat. However, when Historia crushed the serum, threw him, and bashed his claims of godhood, he became erratic and panicked. After the syringe was shattered on the ground, he began lightly crying and desperately licked it off the floor so that he could become a Titan himself.
Rod was the eldest son of Mr. Reiss, the inheritor of the Founding Titan and the true king of humanity. Some time later, he was joined by a younger brother, Uri. Uri and Rod constantly begged their father to release humanity from their encagement, but he always refused, never disclosing why. It apparently had been so many times that Rod was locked behind bars for his attempts, and it is implied to have happened more than once. When it came time for his father to pass his position to a son, Uri volunteered, asking Rod to pray. After Rod observed his father's presence in Uri the moment his brother had opened his eyes, he realized he had become an all-knowing being and protector of the world; God. On his brother's promise, Rod had devoted his time to protecting God and offering his prayers to it.
As a young man, Rod married an unnamed woman and had five children with her: Frieda, Urklyn, Dirk, Abel, and Florian. When Rod was still a young boy, he met Kenny Ackerman when he tried to kill his brother and former king, Uri Reiss. Despite Rod telling Uri several times that they should kill him, especially if he was an Ackerman, Uri refused and apologized to Kenny. This created a bond between the two and Kenny became a servant of the Royal Family, especially to Rod.
Secretly, Rod Reiss conceived a sixth child, Historia, with Alma, one of his maids and confidant. When it was discovered, his mistress and daughter were exiled to a farm that he leased to Historia's maternal grandparents. In the year 842, Frieda devoured Uri and became queen of humanity. However, just like Uri, Frieda fell to the influence of the First King, despite previously promising Rod that she would destroy all the Titans.
On the day that Wall Maria fell to the Armored and Colossus Titan's attack, the entire Reiss family went to a chapel to pray in a secret underground area. However, Grisha Yeager, a Titan Shifter from beyond the Walls, came to talk to the family, asking Frieda to release humanity from their encagement. Bound by the First King's will, Frieda refused and the pair engaged in combat. Despite Frieda's immense power, she was defeated due to inexperience and eaten through the neck. Grisha then attempted to slaughter the entire royal family, with only Rod surviving, due to fleeing blindly. With his daughter's death, he became king of humanity.
Several days later, Rod came to get Historia and inform her that she would be living with him from now on. Kenny Ackerman and the Military Police First Interior Squad intervened and swarmed around Historia and her mother. Kenny questioned if Rod was familiar with the two women, which he then denied. Rod watched as his mistress' throat was slit while she denied being Historia's mother. When the former serial killer moved in to kill Historia, Rod suddenly proposed having her enroll into the Survey Corps and hopefully die in battle. Seeing this as a fitting alternative the First Interior Squad agreed to his demand. This was revealed later to be just a charade invented by him, as up until that point the Military Police making demands of the King seemed somewhat peculiar, and later on Kenny acknowledges having gone along with Rod's plan to get her into the Scouts. Presumably Rod left with the Military Police.
Rod is later seen siding with Kenny in a plan to kidnap Eren Yeager and Historia, eventually succeeding. After Historia and Eren are unlocked from their coffins, Rod undoes Historia's restraints and embraces her, apologizing for everything. Later, he is seen keeping Eren chained hand and foot underneath the Reiss family chapel. He wishes for Historia to devour Eren and regain the Founding Titan, not wishing to become a Titan Shifter himself.
He tries to convince Historia by telling her about the murder of her brothers and sisters at the hands of Eren's father (see above) and revealing to her the true nature of the power inside Eren, the Founding Titan, which would allow her to stop the Titans once and for all. However, Historia asks why all the prior Kings and Frieda never did that if they had such power, and he answers that he does not know, and that the only way to know that is by inheriting their memories.
He compares the overwhelming power of the Founding Titan with God and prays to her, as Uri once asked him to, while he subtly tries to inject the needle into Historia. However, she suddenly remembers her friend Ymir's words about living with pride in her heart, which makes her throw both the needle and Rod as well, accusing him of trying to bribe her with lies.
Seeing his plan fail, he scrounges the fluid off the floor as he watches Historia free Eren, whispering that he will reunite with his father, Uri and Frieda. After ingesting it, he turns into a gigantic Titan, considered by Levi and Armin to be bigger than the Colossus Titan. The Titan is so big that it makes the whole cave crumble.Rod Reiss' Titan then proceeds to ignore the Survey Corps members underneath the Reiss Chapel and begins crawling towards Orvud District of Wall Sheena, hypothesized to be drawn there by the large number of humans in that area. Eren and other soldiers try to get its attention, but it is pointless. He cannot be stopped because of the enormous heat emanating from his body. He arrives there at dawn, when a group of Garrison and Survey Corps members are waiting for him on top of the Wall in order to kill it. The Garrison fires a enormous barrage of cannon fire at Rod, both from the Walls and from the ground. The cannons cause great damage on his back, but he withstands all the attacks and scales the Wall. The intense heat of his body and the wind change forces the soldiers to cover themselves in water to prevent them from being burned. His hands are blown off by Squad Levi with a modified vertical maneuvering equipment attached to a gunpowder barrel, which makes him lose balance and fall over the Wall. After this, Eren, in his Titan form, shoves attached barrels of gunpowder into Rod's mouth, making a enormous explosion and blowing off his head and nape. This was a plan created by Erwin, who predicted that because of his crawling movement his face would be destroyed by the friction, his mouth would be wide open and finally the great heat of the Titan would light the gunpowder by itself. The flying pieces of his body are cut by Squad Levi in order to kill Rod Reiss' human body once and for all. Eventually the piece of his nape is found and cut by Historia, beheading her father and receiving some of his memories in the process, one of which being Rod asking his father to release them from the Titans rule.
- Historia Reiss - Rod was Historia's father, though she is an illegitimate child who is not accepted as a suitable heir to the Reiss family. Thus Kenny Ackerman was charged with her death and the death of Historia's mother. Rod came to get her to live with him, but the Military Police interfered and rather than take back his daughter, Rod was forced to propose an alternative where his daughter's chances of survival would be extremely low rather than see his daughter's death before his eyes. It was thus implied that Rod Reiss may have cared for his daughter. When Eren and Historia were captured, Rod Reiss embraced Historia with tears in his eyes, saying that he was sorry for what has happened, surprising Eren and Historia. The reason for this, may have been his intentions for one day giving Historia the power of her half-sister. However, Historia refused to comply with his wishes that she become a Titan and eat Eren, realizing that the power destroyed her sister's humanity and that Rod was only using her to get the Founding Titan and regain the power of the Reiss family.
- Frieda Reiss - It was implied that Rod loved his daughter over all things. When Historia rejected the serum, he became furious because of the loss of Frieda's memories and power, and when he licked the serum, he said that he will be reunited with his family and with her. In a memory, Frieda bravely told him to allow her to become the next inheritor, saying she would not give in to her ancestors' ghosts.
- Alma - At first she was Rod's servant but eventually she became his confidante and lover. When she got pregnant, she was taken away to her parent's farm. Rod thought that she was the only person that could understand what he was going through.
- Rod Reiss' Titan exposed its internal organs when it stood up, due to all the skin and muscles being worn off as it dragged itself across the ground. His Titan showed digestive organs, specifically the stomach and small intestines, which were speculated by the military to be features that Titans lacked. It is possible that Titans possess these features only as vestigial structures.
- In an interview included in the guidebook Attack on Titan ANSWERS, Hajime Isayama revealed the reason why Rod said he did not inherit the Founding Titan himself: "He thought of himself as just an observer, and in order to preserve the Reiss bloodline, he may have thought that he needed to stay human and make more children. He would have to become the Founding Titan, and he was most likely afraid that he wouldn't be able to fight against the First King's ideology, just like his father and Uri weren't able to."