Nabaste
When someone acts like they're a tough guy, but when it's time to show it, they're as soft as a marshmallow. They talk big, but they're all talk.
He said he'd beat me up, but when I showed up, he ran like a chicken with his head cut off.
She talked about how tough she was, but when I hit her, she cried like a baby.
He bragged about his strength all week, but when I hit him, he looked like he'd never been hit before.