One of his motives in writing them was to have a couple of fantasy heroes closer to true human nature than the likes of Howard's Conan the Barbarian or Burroughs's Tarzan.

The Mouser is a small (not much more than 5 feet (1.5 m)) mercurial thief, gifted and deadly at swordsmanship (often using a sword in one hand and a long dagger or main-gauche in the other), as well as a former wizard's apprentice who retains some skill at magic.

Fafhrd talks like a romantic, but his strength and practicality usually wins through, while the cynical-sounding Mouser is prone to showing strains of sentiment at unexpected times.

In 1936, Leiber finished the first Fafhrd and Gray Mouser novella, "Adept's Gambit", and began work on a second, "The Tale of the Grain Ships".

The stories of Fafhrd and the Gray Mouser respectively were only loosely connected until the 1960s, when Leiber organized them chronologically and added additional material in preparation for paperback publication.

Sundered from us by gulfs of time and stranger dimensions dreams the ancient world of Nehwon with its towers and skulls and jewels, its swords and sorceries.

In The Swords of Lankhmar, it is revealed that Nehwon is just one of many worlds in a multiverse when Fafhrd and the Mouser join forces with a German explorer named Karl Treuherz who is looking for his spacecraft, which he uses to cross the boundaries between parallel dimensions in his hunt for new animals to feature at a zoo.

Ten thousand words of "The Lords of Quarmall" were penned by Fischer early in the development of the series; the story was completed by Leiber in 1964.

The stories have been collected in the "Swords" series: In 2009, Benjamin Szumskyj's Strange Wonders included the first few chapters of "The Tale of the Grain Ships", written in the 1930s.

Several omnibus editions have also been published: In 1972, Fafhrd and the Mouser began their comics career, appearing in Wonder Woman #202 alongside the title character and Catwoman in a story scripted by award-winning SF writer Samuel R. Delany.

Patron warlock of Fafhrd, Ningauble is so named due to his seven (usually only six visible) glowing eyes, seen roving within, and sometimes projecting from, the hood of his cloak.

Along with the Gray Mouser's patron warlock, Sheelba, Ningauble often sends his servant on ludicrous missions such as recovering the Mask of Death or stealing the very stars from the highest mountain.

None knew whether he had the gift of foresight, or whether he merely set the stage for future events with such a bewildering cunning that only an efreet or an adept could evade acting the part given him.

Fafhrd cursed sardonically, then demanded, "But even if I should go clang those rusty bells, how can Lankhmar hold out until then with her walls breached and the odds fifty to one against her?"

[17] While Ningauble dwells in caverns, Sheelba's house is a small hut which strides about the swamps not far from Lankhmar on five chicken leg-like posts, which bend and scuttle like the legs of a great crab or spider.

Although Ankh-Morpork bears more than a passing resemblance to Lankhmar, Pratchett, known for the use of pastiche in his early works, has been quoted as not intending a direct takeoff.

[22] The characters of Barak and Silk from David Eddings' fantasy series The Belgariad are very similar in both form and personality to Fafhrd and the Gray Mouser respectively.

American author Michael Chabon's Gentlemen of the Road (2007) is a "swashbuckling adventure" novel [23] set in the kaganate of Khazaria (now southwest Russia) around AD 950.

[25] The Gray Mouser's dirk "Cat Claw" has appeared as a weapon in several role-playing video games, including early installments of the Final Fantasy series.

In Bethesda's The Elder Scrolls V: Skyrim, when visiting the Ratway in the city of Riften, the first enemies the player meets are a sneaky-looking fellow and a barbarian type called Drahff and Hewnon Black-Skeever.

In Dodge Roll's Enter the Gungeon, the player can encounter a pair of characters named Frifle and the Grey Mauser, styled to look like the eponymous heroes.

In Jack L. Chalker's And the Devil Will Drag You Under, two characters resembling Fafhrd and the Gray Mouser appear briefly in a tavern with one repeating out loud slightly similar names to Ningauble and Sheelba.