A phrase used instead of what the fuck or what the hell when you are in the presence of an adult or little child who you dont want to hear you say fuck or hell etc.
What Scorpion (Mortal Kombat Ninja) saids when shooting out a rope with a tipped Kunai at the end that impales itself in his victims allowing him to pull them closer to him for a free hit.
Old Biff (hitting Young Biff upside his head): It's LEAVE, you idiot! "Make like a tree and leave!" You sound like a damn fool when you're saying it wrong!