Herpes? Really? You have all the time in the world to come up with something good, and you come up with herpes?

That's just sad.

Let's see...in the Fafhrd and Gray Mouser novella "The Lords of Quarmall", one prince of an intrigue-rife subterranean kingdom has assigned his court wizards the task of cursing his brother with a dozen simultaneous noisome degenerative diseases:

From his hours of sitting at the foot of the table, Fafhrd had learned that most of the spells were designed to inflict a noisome disease upon Gwaay: the Black Plague, the Red Plague, the Boneless Death, the Hairless Decline, the Slow Rot, the Fast Rot, the Green Rot, the Bloody Cough, the Belly Melts, the Ague, the Runs, and even the footling Nose Drip.

--Fritz Leiber and Harry Fischer, "The Lords of Quarmall"

(The sorcerers protecting Gwaay from this biomagical assault wind up being suddenly wiped out en masse by friendly fire; suffice to say that Little Bro does not get to leave a good-looking corpse.)