After completing the previous main quest, the Coon will request your presence to the Coon Lair. Go to the basement and after the scene, you’ll be able to select your fourth class. Two new classes will be available: Plantmancer and Martial Artist. The two new classes are pretty straightforward and may have limited inclusion to your current power loadout. Nevertheless, you still have to select a preferred class and complete the tutorial battle in order to complete this mission.