As noted before, the Indo-European word for panther is peculiar for having a syllabic r in the root *prd, as shown by Sanskrit prdaku and Greek alternation in pardalis, pordalis. In addition the syllabic r was stressed.
This feature occurs in a number of other Indo-European words: *wlkwos ‘wolf’, H2rtkos ‘bear’, *wlp- ‘fox’ and *glH1is ‘dormouse’. The word for panther is therefore integrated in a paradigm of names of wild animals, which share the unusual feature of having a stressed syllabic l or r.
Even though this root *prd is not widespread among Indo-European languages, there is some internal linguistic reason to think that it must be inherited. A connection with PIE *per(k) ‘speckled’ is plausible. In addition it is interesting to note that Greek parthenos ‘virgin’ is phonetically similar to pardalis, pordalis ‘panther’. This coincidence probably sheds some light on the association of goddesses of fertility and panthers in Anatolia.