The paper investigates the etymologies of several species of reptiles, amphibians, and birds whose names draw on the ancient cattle-sucker myths rooted in cultures of Indo-European origin. New or corrected explanations are suggested for a number of animal names, including the Lithuanian žal(k)tỹs 'grass snake', South Slavic *guja 'snake, viper', Hittite akuu̯akuu̯aš 'toad', which seem to confirm a primitive conviction of prehistoric people that some frogs, toads, lizards, snakes, and even birds drink milk and are able to take it directly from udders.