how have I not seen this before?
From Hark! A Vagrant, "Anne of Cleves Gables":
http://www.harkavagrant.com/index.php?id=348
(...oh man, I have just remembered that I recently tried to make a serious point in a debate about Macbeth by describing that Kate Beaton comic where Macbeth reacts to the "Banquo's sons will not be kings, but will beget kings" prophecy by going "KILL EVERYONE" whereas Banquo goes, "haha, our kids are totally going to hook up." *facepalm*)
http://www.harkavagrant.com/index.php?id=348
(...oh man, I have just remembered that I recently tried to make a serious point in a debate about Macbeth by describing that Kate Beaton comic where Macbeth reacts to the "Banquo's sons will not be kings, but will beget kings" prophecy by going "KILL EVERYONE" whereas Banquo goes, "haha, our kids are totally going to hook up." *facepalm*)