Uda no Parasite

Uda's Parasite is logical but much more openly expressive than many members of his species. He smiles frequently, jokes and speaks casually, traits that may partly reflect the human entertainment he watches with Uda.

He can be insensitive toward Uda, particularly regarding emotional reactions such as crying, which he struggles to understand. Their exchanges often resemble arguments between mismatched companions rather than the relationship between a predator and its host.

Despite this bluntness, he repeatedly acts to preserve Uda's life. His survival depends on Uda, but their long-term cooperation develops beyond the immediately hostile relationship seen between many Parasites and humans.

Uda's Parasite can transform the lower part of Uda's face and neck into blades and other structures. He can sense Parasite signals, harden his tissue and manipulate the host body's physical functions.

His unusual location gives him access to Uda's chest. This allows him to reposition internal organs during an attack, potentially moving vital structures away from an incoming strike.

His position also creates disadvantages. Large transformations around the mouth and neck can interfere with Uda's breathing, reducing his endurance during prolonged combat.

Uda's Parasite meets Shinichi Izumi and Migi when the pair detect another Parasite signal near Sakurazaki. The meeting reveals that Shinichi is not the only human whose infection failed to reach the brain.

He explains that he entered Mamoru Uda through the neck, but Uda fell into the sea during the attack. Faced with the imminent death of his prospective host, the Parasite abandoned its attempt to reach the brain and instead matured around Uda's jaw and chest so that it could keep him breathing.

He later helps Uda fight the Parasite occupying Nobuko Izumi's body, manipulating Uda's internal organs to prevent a chest wound from becoming fatal.

As public awareness of the creatures increases, Uda stops simply calling his companion "Parasite" and gives him the name Jaw.

Mamoru Uda is the human host whose jaw and neck the Parasite occupies. Their survival is mutually dependent, and the two develop a cooperative partnership.

Shinichi Izumi becomes an ally after both pairs recognize the similarity of their incomplete infections.

Migi shares Uda's Parasite's unusual condition of living in a human body without controlling the brain.

Nobuko Izumi has her body occupied by the hostile Parasite that Uda and his companion help Shinichi confront.