Interesting actually, as the salamander was "always" associated with fire. It was also usually the "good guy".
"This has no digestive organs, and gets no food but from the fire, in which it constantly renews its scaly skin. The salamander, which renews its scaly skin in the fire,—for virtue." - da Vinci. It was also common in heraldy and was a symbol of enduring faith.
Which actually fits quite well with Rachel and it's corrupted faith considering Ktullanux is of opposite element. Assuming it's not all just a coincidence. And it probably is.