Where does “żmiisko” come from?

żmiisko (Polish) comes from Polish Żmija, from Old Polish źmija, from Proto-Slavic zmьja, from Proto-Indo-European dʰéǵʰōm, from Proto-Indo-European -ōm, from Proto-Indo-European -mi.

Ancestry of “żmiisko”, step by step

StepLanguageWordMeaning
1PolishŻmijaviper, adder, especially a viperine
2Old Polishźmijaadder, viper
3Proto-Slaviczmьjasnake
4Proto-Indo-Europeandʰéǵʰōmearth
5Proto-Indo-European-ōmemphatic suffix or postpositive particle
6Proto-Indo-European-mi—
Every word from Proto-Indo-European -mi →Every word from Proto-Indo-European -ōm →Every word from Proto-Indo-European dʰéǵʰōm →