Children
Elphaba didn't like the other kids at her elementary school. They teased her every day, and by the second week young Elphaba was sick of it.
So she decided to get revenge.
The next time they approached her, she smiled when they called her names.
"You better watch out."
They blinked, confused.
"I'm actually a witch, and if you don't stop I'll zap you!"
A chair nearby seemed to levitate and float towards them.
The children never teased her again.