jack jack
A good person who will let you walk all over them, but when you push too far, they flip out and turn into a total monster. Just like baby JackJack from the Incredibles, but way more intense.
He let me make fun of him all day, then he kicked my ass in the hallway.
She was nice until I said her name was 'chicken nugget.' Then she screamed and threw a chair.
He was calm until I called his mom a 'dumb bimbo.' He punched me.