Where does “sharkie” come from?

sharkie (English) comes from English shark, from German Schurke — villain, scoundrel.

Ancestry of “sharkie”, step by step

sharkie traces back through two separate lines of ancestry.

via English shark

StepLanguageWordMeaning
1EnglishsharkA scaleless, predatory fish of the superorder...
2GermanSchurkevillain, scoundrel

via English ie

StepLanguageWordMeaning
1EnglishieAlternative form of i.e
Every word from German Schurke