Chuth is an older adult Nieznane with several lairs in the Misty Forest (and likely another in Trollbark Forest). He served Prince Neron-Vain, son of King @melan, who had turned on his father and joined the Cult of the Dragon, becoming the Green Wyrmspeaker.
An attack on one of his lairs by the Yungbluds (working for the Council of Waterdeep on behalf of the Emerald Enclave) resulted in a release of hellfire by the Tiefling Alyks Askaria, permanently destroying one of his wings. Chuth's singular focus is revenge upon all involved, in particular the wizard.