Calvin and Hobbes by Bill Watterson for January 24, 1990
Miss Wormwood: Calvin, would you please demonstrate the homework problem you were assigned yesterday? Calvin: I wasn't here yesterday. Miss Wormwood: Yes, you were, Calvin. Didn't you do your problem? Calvin: I'm not Calvin. I'm duplicate number five. Duplicate two was here yesterday, not me. We're all taking turns. Number two will be back next week, and you can ask him to do the problem then. Look, I don't see what's so hard about this!