Dot Pyxis (ドット・ピクシス Dotto Pikushisu?) is the commander (司令 Shirei?) of the Garrison, and is in charge of the defense of the southern region. He is the highest ranking administrator of the southern region, which includes Trost District. In matters of defense, he is given full authority.
Pyxis is a bald man with a structured build. He has gold eyes and a distinguished mustache, with light skin and notable wrinkles under his eyes. As a commander, he also wears a purple bolo tie, much like his fellow commanders Erwin Smith and Nile Dawk. As the highest ranking Garrison officer, he is only seen wearing his Garrison uniform paired with a white button-up shirt and a red sash with gold trim.
Pyxis is an eccentric man. While observing Titans breaching Wall Rose, he said he would not mind being eaten by a Titan if "it happened to be a stunning beauty." He retains a calm, and light-hearted demeanor, even in the midst of chaos, and he understands the strife and suffering of others, as he is seen allowing soldiers who wanted to leave because he understands the extreme amounts of terror and fear in those soldiers. Yet, Pyxis is an effective leader, as seen when he quiets all the soldiers attempting mutiny and successfully convinces them to continue fighting to retake Trost. He is an expert strategist and is able to gauge a situation carefully, but also knows when to take risks, which lead to his decision to trust Eren Jaeger to stop the breach. However, he stated himself that he is a sore loser, and along with this, he says that the idea of giving up to the Titans makes him sick, representing his determination to attempt to defeat the Titans and save humanity. He is a man who makes smart choices, putting Ian Dietrich in charge of the elite squads protecting Eren proved to be a wise move as Rico Brzenska and Mitabi Jarnach both called that they should give up on the operation, which Ian denied, that eventually led to being a success.
Pyxis first appears during the Invasion of Trost, playing chess with Lord Wald. A soldier appears and informs him of the situation in Trost, which required his immediate attention. Pyxis decides to head over to the scene, calmly refusing the noble's request to stay and protect his property.After it was discovered that Eren Jaeger could transform into a Titan, Eren was sentenced to death. Pyxis, however, happened to be nearby when Armin Arlelt gave a passionate speech in defense of his friend, vouching for the strategic and tactical benefits that he could bring to turn the tide of the battle. The officer in charge, Kitz Woermann, was not swayed, but as he was about to give the kill order, Dot Pyxis stopped him, believing Armin's words. Pyxis brings the three soldiers on top of Wall Rose and clears up the matter of Eren's transformation by saying he will see the proof in Eren's basement. He questions Armin about his plan to use Eren's Titan from to seal the hole in Wall Rose and is so encouraged he decides to use it. He calls up his staff officers to begin planning for the assault. However, the Garrison, already extremely low on manpower and morale after the evacuation, is in no condition to fight again and many soldiers attempt to mutiny in order to spend the little time they have left with their families. In order to give the soldiers hope, he introduces Eren as being a part of a secret government experiment to turn humans into Titans to fight them on equal footing. Unsurprisingly, Pyxis is not taken seriously and soldiers turn to leave, some even fighting each other. Finally, he gives an order to pardon all deserters, which shocks higher ranking soldiers. However, he states that by leaving, they will put their families at risk and expose them to the same terror that has paralyzed themselves. This argument convinces the soldiers to reassemble their ranks and begin the operation. Pyxis assembles an elite squad, placing Ian Dietrich in charge. He gives the elite squad the orders to protect Eren Jaeger, whilst acting at their own digression.
Pyxis reflects on the troops he had sacrificed by authorizing the operation to retake Trost District. He admits he would gladly be remembered as a murderer for the sake of mankind's survival. He continues to oversee the operation, ordering his men to continue luring the Titans to the corner of town, and keeps this stance even once the elite squad meet difficulty. Pyxis' operation ends in success, and mankind's first victory over the Titans, with the gate to Trost being successfully plugged. Pyxis then deploys reinforcements to rescue the elite troops.
Pyxis later meets Commander Erwin Smith atop the Wall, and the two speak about the trial to be held to decided Eren's fate. Pyxis informs Erwin that the outcome of the trial will be decided by Dhalis Zachary, depending on if Eren is beneficial or not to mankind. Later, Pyxis attends the trial. When questioned by Dhalis Zachary, he informs the courtroom that it is impossible to launch an expedition from Trost.
Pyxis receives word from a member of the Garrison that Wall Rose has been breached. The next day, he is found sleeping atop the Wall in Trost, until his aide, Anka Rheinberger, awakens him with a slap. He is scolded for drinking too much alcohol, and told that she does not want to care for him by changing his nappy. Anka reports the lack of Titans spotted within Wall Rose and he surmises from this that the Wall has not been breached. Erwin Smith arrives shortly and Pyxis congratulates him for capturing the Female Titan. He also hopes that the invasion of Wall Rose will convince the nobles in the interior to reconsider their motives.
Shortly thereafter, one of his soldiers reports in, confirming that Wall Rose is still intact. Pyxis is informed that three Scout Regiment recruits from the 104th Cadet Corps are Titans. The Garrison's advance squad witnessed a fight break out on top of Wall Rose between the Scouts and the Armored and Colossal Titans, but the fight was over by the time they were able to help.
Following the rescue of Eren Jaeger, Pyxis meets with Levi and Erwin at the latter's bedside, since Erwin lost an arm in the battle. Hange Zoë reports in along with Conny Springer regarding their findings at Ragako Village. Pyxis asks if that is the village the Titan invasion originated from and Hange confirms it. She has a hypothesis that the villagers and the Titans are the same.
- The name "Pyxis" may refer to the constellation "Pyxis Nautica" - Latin for "The Naval Compass".
- In 2010, Isayama posted a blog post admitting that Dot Pyxis was modeled after General Yoshifuru Akiyama, a general in the Imperial Japanese Army, to whom Isayama said "I respect for leading such a simple and frugal life". This brought a large controversy and even death threats against the mangaka that lasted for years (and may still continue to this day) from sectors of the population where Yoshifuru is deeply hated. 
- In an issue of Bessatsu Magazine, Isayama revealed that Pyxis is married and has children.