|Killer T Cell|
|ROMANJI||Kirā Tī Saibō|
|ALIASES|| Memory T Cell|
Oaf (by Natural Killer Cell)
|AFFILIATION||Killer T Division|
|OCCUPATION||Pathogenic Cells Killer|
|ANIME DEBUT||Episode 1|
|MANGA DEBUT||Chapter 1|
Killer T Cell (キラーT細胞 Kirā Tī Saibō?) is a minor character in Cells at Work!
He is a white blood cell, specifically a T Lymphocyte (Killer T Cell) that works under the Killer T Division. He is tasked to kill any foreign entities and cells that are damaged or infected.
He is a tall, masculine cell with tan skin, blond hair, and gold eyes. He wears the killer T cell uniform.
Killer T Cell is loud, obnoxious, and quick-tempered, resulting in rivalries with many cells. He also despises it when a non-white blood cell forms a friendship or relationship with one of his kind.
As an apprentice T Cell he went through training at Thymus school where apprentices learn to become T Cells. Although in the beginning he was scrawny and weak, he never gave up. There he also met Helper T Cell. They end up forming a grudging friendship.
Killer T Cells are strong cells who play an important role; they kill cancers cells, infected cells as such.
- Overall Abilities: Like all killer T cells, he is tough and masculine. Possessing heightened strength, he can easily terminate threats with one strike and break walls of tissue.
- Martial Arts Proficiency: He can wield other weapons like a knife, but free hand is his preferred choice. His attacks are packed with a lot of strength, thus one punch can kill threats like influenza infected cells.
- T Cell Perforin Canon Punch: A legendary killer T move that only can be unleashed when one's desire to protect the body is at its limits. He was able to utilize the special technique once during the final Cancer Cell arc. It is unknown whether he will be able to use the technique again in the future. 
- Memory T Cell: Killer T Cell can take the role of a Memory T Cell when fighting an enemy he has fought before, signifying that he is familiar with most of the enemy’s moves and is using that knowledge in combat.
- He secretly named his fist attacks during his youth, being called "Immunity Super Dissolving Fist!", "Killer T Punch, 42 Strikes!", and "In Vivo Ultimate Secret Technique Antigen Super Pummeling Smash-Into-Pieces Fist!".
- Natural killer cells and killer T cells resembles brothers-in-arm because of their complementary roles for each other. This explains the close yet competitive relationship between NK Cell and Killer T Cell in the series.
- ↑ Cells at Work! Manga, Chapter 25