Cats are a species of small predatory carnivorous animals that were valued by humans before the Great War for their companionship and ability to hunt vermin, such as rodents, snakes, scorpions, and other household pests.
After the Great War, many cats in what used to be the United States were hunted for food because they were an easy prey until few domestic specimens were left, although some still survive as witnessed in The Commonwealth.
Rumor is that the last known living cat in America, Mr. Pussy, died in Carbon, Texas in 2208. Ruby the prostitute wanted to find him when he got lost, and asked the Initiate to help. They discovered the cat's corpse in the Carbon Crater and brought it back to Ruby.