Goat
The goat, a small horned ruminant, originally came from the Middle East and Central Asia. One of the earliest domesticated animals, goats spread across the world with human farmers. After collapse, domesticated goats quickly went feral.
#Human relations
People of the Fifth World hunt goats for meat and make clothing from their skins. They also use their intestines for sewing thread and stringed instruments, and make decorative crafts from their horns.
#Specialization
A community that specializes in relationship with goats will likely tend towards hunting and gathering, following the semi-feral flocks of goats as they travel. They may live in a particularly mountainous region, where goats thrive because of their agility and climbing skills. Such a community may live in collapsible houses of animal skins -- goat and otherwise -- and wear goat hide (or woven goat fur) for their clothing. They may hunt goats in the mountains for part of the year, then move into more low-lying regions another part of the year to hunt other animals.
Because small-scale herders often kept goats and sheep together during the Fourth World, the animals' feral descendants may keep this tradition, living alongside each other in hilly, marginal areas. Therefore, a community specializing in relationship with goats may also specialize in relationship with sheep, as the two survivors of human domestication roam close by, though no longer together -- as feral rams and bucks tend to butt heads (literally).
A community specializing in relationship with goats might take inspiration from the goats' excellent climbing skills and become known as great climbers themselves. Alternatively (or additionally), they may practice archery so they can shoot the goats from a distance without having to attempt scrabbling up cliff faces quietly and stealthily. But when not hunting, they may hold rock-climbing in high esteem, perhaps even competing with each other over who can climb the highest, most dangerous rock faces.
A community specializing in relationship with goats will admire goats' curiosity and adaptability, almost certainly incorporating goats into their folklore, likely as a trickster character. They will notice when the goats -- usually not too picky about food sources -- shy away from eating plants that grow in a particular area. In this way, goats may teach them which places civilization left strange and dangerous contaminants.