Calvin and Hobbes by Bill Watterson for November 03, 1992
Transcript:
Calvin: Look, Hobbes, I got a mysterious letter! The return address is a skull with X-ed out eyes! It has a local postmark, though. So I must know the person. Hobbes: Oh boy, intrigue! Calvin: But who would send me an anonymous, weird letter like this? Hobbes: Maybe a girl! Calvin: Gaaaa! Doesn't the post office screen anything?! Hobbes: I'll get you some gloves!
Get a hazmat suit.