Zhdez starships almost invariable have a cat, or zechche aboard. Zhdez domestic cats vary in size more than Terran ones do, though not as much as Terran dogs: they range from 5 to 60 pounds, though shipboard animals tend to the smaller end of that scale. They are longer-legged than Terran cats, tending to look larger than their actual weight.

Most are hybrids of two different feline species. The larger one has filled the same niche as domestic dogs on Earth: a pack hunter with blunter, less retractile claws similar to a cheetah's, built more for running down prey than ambush hunting. The smaller one is more similar to the Earth housecat: an expert climber and ambush hunter domesticated for pest control.

The pack hunter, like many Zhdez species, has a primitive telepathic ability, and the domestic version has been bred to be sensitive on the human "wavelength." A shipboard cat will regard the crew as its pack, including non-telepathic members (and mechanical ones, with sometimes comedic results).

The Zhdez cat is popular among Inukari as well, since they get along well with the traditional Inukari housepets, kuga. Terrans have been of mixed feelings: Terrans' love for hybrid wild cats like "Savannah cats" transferred to the zechche, but their telepathic sensitivity makes them unfashionable in the Terran Core.

The origin of the common name is in dispute: "chchch" is the Zhdez equivalent of "pspsps," but it's not clear whether that came from the name or vice versa.