Young Biff: Why don't you make like a tree and get out of here? Old Biff: It's leave, you idiot! "Make like a tree, and leave." You sound like a damn fool when you say it wrong. Young Biff: All right then, leave! And take your book with you!
Old Biff: Hello? Hello? Anybody home? Huh? Think, McFly! Think! Your old man, Mr. Loser? Marty McFly: What? Old Biff: That's right. Loser with a capital "L". Marty McFly: Look, I happen to know that George McFly is not a loser... Old Biff: [interrupts] I'm not talkin' about George McFly. I'm talkin' about his kid! Your old man, Marty McFly Sr.? The man who took his life and flushed it completely down the toilet. Marty McFly: I did? I- I mean he did?