My first exposure to Fritz Leiber's characters Fafhrd and the Gray Mouser was actually through the Advanced Dungeons and Dragons supplement, Deities and Demigods. The original version had several mythos that were later removed for copyright reasons and Fritz Leiber's creations was one of them. Some of the creatures just fascinated me - ghouls with green transparent skin so all you can see is their skeletons, the wizards Ningauble of the Seven Eyes and Sheelba of the Eyeless Face, etc.
Fafhrd is a hulking northern barbarian with wild red hair and beard. The Gray Mouser is a slightly built and cunning child of the city streets. Through fortune they find themselves allied in common cause in the crowded city of Lankhmar. That cause, of course, being themselves.
I'm sorry to say that I didn't actually get my hands on any of the stories until Mike Mignola did a comic book version in 1991. I was now fully hooked on the barbarian and his sneaky companion. I fell in love with Mignola's art the first time I laid eyes on Hellboy and it lent itself so well to the mean streets of Lankhmar.
When White Wolf published this edition of Lean Times in Lankhmar with a cover by Mike Mignola I absolutely had to own it and all the other collections in the series.
I'm pretty sure I've got those comics in box here somewhere...