Quote from Ross in The One Where Underdog Gets Away
Ross: Is Carol here? Susan: No, she's at a faculty meeting. Ross: I just came by to pick up my skull. Well, not mine, but... Susan: Come in. Ross: Thanks. Well, Carol borrowed it for a class, and I have to get it back to the museum. Susan: What's it look like? Ross: Kind of like a big face without skin. Susan: Yes, I'm familiar with the concept.