Abstract This paper presents a detailed etymological analysis of words for ‘fox’ in Indo-European (IE) languages. We argue that most IE ‘fox’-words go back to two distinct PIE stems: *h₂lō̆p-eḱ- ‘fox’ and *ulp-i- ‘wildcat, fox’. We provide a revised analysis of the etymology and relationship among the various Indo-Iranian ‘fox’-words, and we argue that Baltic preserves remnants of the ḱ-suffix found in Greek, Armenian, and Indo-Iranian. Additionally, we describe how *h₂lō̆p-eḱ- was borrowed from Indo-Iranian into Uralic and we outline the relationship among the reflexes of this word in various Uralic languages. Finally, we reconstruct the paradigm of *h₂lō̆p-eḱ- as a unique type of hysterodynamic stem, which nonetheless has close parallels in PIE. We observe that a similar ḱ-suffix is found in PIE adjectives and animal names.