There are lots of snakes in Ustalav, but they're small and poisonous, not gigantic rolls of strangling muscle. Perhaps a sailor brought Lunesca to the port of Caliphas from some distant, exotic locale, and lost her in a poker game. Or perhaps she was imported at great expense by some scholar of Lepidstadt, and promptly escaped his laboratory. Or perhaps she was summoned by some wild magician, and happened not to wink out when the magic should have ended.
Who knows? If she remembers, she's not telling. Luneca seems to enjoy being a bit of a mystery. She also seems to have an unusual sense of humor--which is to say, she seems to have one, which seems unusual in a snake.
