Calvin and Hobbes by Bill Watterson for September 29, 1988
Hobbes: I guess we should go home to earth. Calvin: Yeah, we may not be welcome here. We ought to fix up our own planet before we go messing around with other people's planets. Afterall, there's only one earth, and it's got to last us a while. Hobbes: We also should go home because we're out of tuna. Calvin: I hope Mom and Dad didn't rent out my room.