Big Mac wrote:Are they also supposed to be wererats in Lankhmar novels, or is that something where the Lankhmar story has been adapted to fit with the mechanics of D&D monsters?
They're not supposed to be anything in the Lankhmar novels, because these characters (including the character on the cover) were created for Cutthroats of Lankhmar
. They're allied with the rats of Lankhmar Below, who in the novels are a group of 13 super-intelligent rats who lead ordinary rats, but the wererats aren't supposed to be the same thing as them.
There's a little bit of information on the super intelligent rats of Lankhmar in 2nd edition Legends & Lore, page 156, under "Cults of the Beast." There are only 13 of them.
Although the AD&D Lankhmar line attempted to simulate Fritz Leiber's novels, they were also AD&D supplements aimed at the audience of AD&D players, so sometimes they'd add AD&D creatures that weren't in the novels, but the authors thought could fit in the world anyway. This is an example of that. Fafhrd and the Gray Mouser never fought wererats in the normal AD&D sense of the word, but you could imagine them doing so.
As I mentioned in another thread, though, one of the sailors in The Swords of Lankhmar
mentions that he believes a character is a
"were-rat," so at least the concept of wererats exists on the world of Nehwon.