Over the Edge
Barbarians come alive in the chaos of combat. They can enter a berserk state where rage takes over, giving them superhuman strength and resilience. A barbarian can draw on this reservoir of fury only a few times without resting, but those few rages are usually sufficient to defeat whatever threats arise.
The base Barbarian is found in the 5E Players Handbook, a pdf for the PHB can be found here.
Customization for the Barbarian consists of choices for Primal Paths (all Barbarian options shown below):