Doonesbury by Garry Trudeau for August 10, 1971
Transcript:
Bob: Mark, the reason I asked you to visit is simple; I'm about to do some undercover work, and I need to know from you the mannerisms of the drug culture. Mark: You must be crazy! You think I would help you and the F.B.I. nail my own kind! Bob: You better. We've got a file on you this thick. Now then, how often do you bathe?