bufo.

Probably loaned from a different Italic language such as Oscan, where the word could have referred to any creeping small animal such as a hamster. The connection with Proto-Slavic *žaba (“toad”) is uncertain, as the initial vowel cannot reflect a common Indo-European origin. Usually connected with Latin bōs, bovis (“cow”), reflecting an ancient folk belief that toads — among other animals — were thought to steal milk from livestock. More specifically, būfō is derived from an ancient compound of Proto-Indo-European Proto-Indo-European *gʷṓws (“cow”) and *dʰeh₁(y)- (“to suckle”). A very close parallel to this derivation can be found in Albanian thithëlopë (“toad”, literally “cow-sucker”). Compare typologically Latin caprimulgus (“nightjar”, literally “goat-milker”), Proto-Slavic *(s)mъlžь (< Proto-Indo-European *h₂melǵ-, whence also English milk).