Theretta Belwin
Voiced by: Casey Robinson
One of Niamh's and Connie's classmates at Teras High School, Theretta never seems to tire of giving Niamh a hard time. It's nothing personal, though; Theretta's mean to pretty much everyone except for a small clique of hangers-on. She's a bully whose love of causing other people grief is only rivaled by her love of opera.