- "There's this one thing I've been thinking about for years. Say you're a nice thing, right? And there's a mean thing that turns nice things into mean things. But, you caught it. Would you kill the mean thing once and forevers, or would you maybe take the mean thing and put it someplace safe so people in the future could find it, feed it to some dogs? I'm just saying that I might probably not do the second one."
- — Dimkee Hotay
Pheru were a species of small animal favored by prehistoric humans and San'Shyuum as pets. Originating from Faun Hakkor in the Charum Hakkor system, they were natural herbivores noted as being lively and gentle in behavior. While normally kept as pets, the Pheru were also edible and consumed by some humans as food. They were the vectors of the first Flood outbreak in the Milky Way Galaxy.
Around 98,445 BCE, humans discovered ancient, derelict ships of unknown origin bearing a fine, desiccated powder consisting of inert, short-chain organic molecules. Research shed no light into the origins or purpose of this material, although it was deemed harmless. However, experiments demonstrated it had minor psychotropic effects on lower animals, including the Pheru, resulting in more favorable behavior. Due to this behavioral alteration, the powder began to circulate on black markets across humanity's interstellar empire, and Pheru treated with the powder became coveted and expensive.
Over several centuries, no ill effects seemingly appeared. The behavior of the Pheru continued to exhibit more qualities seen as positive; however, at the same time, it was altering their genetic code. This first appeared as loose growths of soft fur between the shoulders of roughly a third of the Pheru population. This was seen as another desirable trait, and specimens of this type were favored particularly among the San'Shyuum. Soon, however, other Pheru began to consume these fur growths — and even the animals themselves. This acted as a sort of trigger for more drastic changes that had been stirring in their genome: the Pheru began to grow striped rods and other gruesome fleshy growths. These growths as well as the animals affected by the disease were ravenously consumed by fellow Pheru, which began suffering widespread abortions and genetic deformities.
Most of the affected animals were euthanized by their human and San Shyuum masters, but despite feverish research no cure was discovered. However, most researchers failed to see the connection between the powder and the deformities, believing the Pheru had simply become overbred. Many were released to their natural habitat of Faun Hakkor. However, some humans who consumed Pheru meat soon began to exhibit similar growths and behavior as the animals previously had, beginning the parasite's first outbreak.
List of appearances
- Halo: Cryptum (First appearance)
- Halo: Silentium (Mentioned only)
- Halo 5: Guardians (Indirect mention)