Thrax is a member of the Villain League, and the Big Bad of Osmosis Jones. A tall, extremely virulent, and unusually powerful pathogenic agent, he claims loudly: “Ebola is a case of dandruff compared to me!” and has killed numerous people before arriving in Frank. He carries a chain consisting of numerous chromosomes removed from other victims' hypothalamus as a trophy. His primary motivation for his infections is to go down in medical history as the world's deadliest virus and with each new body goes on to break his previous records. His left index finger is a long claw, which can melt the cellular equivalent of steel, consume cells and other viruses in flames, and alter the properties of other cells. His claw can even melt synthetic polyester fiber (though at a much slower rate), a feature that comes into play at the climax. His name is a play on the word La Muerte Roja, which is the Spanish name of Red Death, Also, his name is from Anthrax although he does not cause the disease. It has never specified what kind of disease he causes, but he is mostly likely to be a fictional pathogenic agent. Thrax is killed at the film's climax when he falls into a beaker of rubbing alcohol where he violently dissolves to his death.
In Spongebob or Spyro meets Osmosis Jones, Thrax reprises his role from the film. For a brief time during development, Thrax was going to be a Dark Spawn Lord of Pestilence and Sickness, but was ultimately degraded to that of a Villain Leaguer. the whole thing itself won't be considered, cause Scroopfan does not like the idea of the human body (exspiecally that of a gross man) would be considered a world, and does not want to do the project period.