Feral

Founding race: Bestia

We do not fear the creatures, for we are the creatures.

Languages: Feral and one other founding language.

The Bestia races, such as Dragonborn, Tabaxi, or Aarokocra abandoned the old ways and ran with the creatures of land, eventually taking their form. When born each child takes the form of the elder race but immediately connects with animal spirit. By the age of two the child takes on a form and mannerism of their animal.

Example races. Dragonborn, Aarakocra, Kenku, Lizardfolk, Loxodon, and Tabaxi

Half-kin

Languages: Feral and either one founding language or Oric.

Half-orcs and Goliaths represent a hybrid of any of the goblinoid, orc, or giant races and any other race. These almost always live with their monstrous parent but some choose to live with Feral races. They are treated with a touch of suspicion.

Shifters

Languages: The founding language where they were raised.

Any mingling between the Bestia and other races produces a Shifter (using Eberron rules). Two shifters are equally likely to produce a founding/child race, a shifter, or a full Bestia.
Shifters can be found in both Feral culture and in any of the other three. They are as much at home in their culture as any other.