Where does “зверюго” come from?

зверюго (Bulgarian) comes from Bulgarian звяр, from Proto-Slavic zvěrь, from Proto-Balto-Slavic źwēˀrís, from Proto-Indo-European ǵʰwer- — wild; wild animal.

Ancestry of “зверюго”, step by step

StepLanguageWordMeaning
1Bulgarianзвярwild animal, beast; brute
2Proto-Slaviczvěrьwild animal, beast
3Proto-Balto-Slavicźwēˀríswild animal, beast
4Proto-Indo-Europeanǵʰwer-wild; wild animal
Every word from Proto-Indo-European ǵʰwer- →Every word from Proto-Balto-Slavic źwēˀrís →Every word from Proto-Slavic zvěrь →