problem child
Refers to a child who causes trouble or is difficult to manage, often in a school or family context. Can also be used figuratively for a person or entity that is a source of trouble.
He is the problem child of the class.
That kid is treated as a problem child.
He's been the troublemaker of the class since way back.
The teacher treated him as a problem child and always scolded him harshly.
She's known in the industry as a troublemaker.