Nabaste
Someone who talks tough and acts like a beast, but when it's time to fight, they're as weak as a worm. They're loud, but they're not real.
He said he'd beat me up, but when I showed up, he ran like a coward.
She said she'd take me on, but when I hit her, she cried like a baby.
He talked trash all week, but when I hit him, he looked like he'd never been hit before.