Dot Pyxis is a high-ranking military commander in the Paradis Island Garrison regiment, having held the position of Garrison Commander for Wall Rose's southern territory for many years. An elderly man with a pragmatic, often cynical view of human nature and governance, he demonstrates a calm, strategic mind in crises. Pyxis personally directs the defense of Trost District after the Colossal Titan breaches its gate, coordinating counterattacks and civilian evacuations.

Recognizing both the strategic value and peril of Eren Yeager's Titan abilities, Pyxis endorses the plan to deploy Eren in sealing Trost's gate, fully aware of the risks. He later authorizes the Survey Corps' mission to capture the Female Titan within Stohess District, accepting the resultant civilian casualties and property destruction.

When Titans within the Walls and the royal government's true nature are exposed, Pyxis becomes instrumental in Erwin Smith's military coup. By publicly backing Erwin and using his influence to rally Garrison troops, he ensures the coup's victory over the Military Police and the false king, earning promotion to overall Commander of the Garrison regiment.

During Marley's surprise assault on Paradis, Pyxis attends defense planning sessions. He falls victim to a conspiracy that taints wine with Zeke Yeager's spinal fluid, distributed to high-ranking officials and military personnel loyal to Paradis' new government. After consuming the contaminated wine, Pyxis transforms into a Pure Titan upon hearing Zeke's scream. His Titan form wanders aimlessly among others similarly transformed within Paradis Island, marking the conclusion of his story.