The most maligned of Pern's dragonkin, whers are generally regarded as little better than oversized guard dogs by most people. They are typically viewed as being ugly and brutish, but their reputation (and people's perceptions of them) are more based on cultural bias rather than fact. Whers are not as intelligent or as empathic as dragons, but they are far more independant and hardy. Like dragons, who are their genetic cousins, whers were genetically engineered to fight thread. Unlike dragons, they don't flame: they are hardy enough to eat thread, and packs of whers led by their queens will range out instinctively to fight this foe at nighttime. Whers are nocturnal, and unlike dragons, have ears, smooth eyes (the refracted lenses are turned inwards) and vestigal wings. Bizzarely enough, whers can fly using innate powers of telekinesis, but they cannot do it for long periods. They can jump in between, but doing so is riskier, as whers are not hardly as intelligent as their more refined cousins.

Whers are photophobic and must be kept in dark caves and corridors during the day, roaming at night. Wherhandlers bond with wherlings by feeding them, and then sharing their own blood with them, which makes them tractable. They speak with their owners telepathically, always addressing themselves in the third person. Wher names are formed by taking the last syllable off the end of the hander's name and adding -sk.

The largest queen whers stand approximately 19 hands at the wingshoulder, while the smallest greens stand at about 16, the size of a large horse.