Cold Woman has a bizarre list of powers. “This creature is basically a huge white pudding. Her powers include illusion generation…” “Her corrosive secretions dissolve metal at the same rate as a black pudding.” “Cold Woman lures persons into her lair with gems and jewelry, which are scattered about her cave. She then paralyzes them and inserts one of her eggs into the body.” “Her young are known as Cold Spawn.”
I don’t remember any such creature anywhere in Leiber, but I did find this passage from The Jewels in the Forest that I think may have inspired whoever wrote up Cold Woman. Fafhrd rants:
“Oh, by Glaggerk and by Kos!” he roared. “By the Behemoth! Oh, by the Cold Waste and the guts of the Red God! Oh! Oh! Oh!” Again the insane bellowing burst out. “Oh, by the Killer Whale and the Cold Woman and her spawn!”
That’s all I can find: 6 words, “Cold Woman and her spawn.” From that, the author (Ward, or Kuntz, or whoever) presumably spun the rest of the entry: the combat stats, the adventure hook, and the classic first-edition PC-devouring egg attack.