The story
From blood + thirsty. Cognate with West Frisian bloeddorstich (“bloodthirsty”), Dutch bloeddorstig (“bloodthirsty”), German blutdürstig (“bloodthirsty”), Danish blodtørstig (“bloodthirsty”), Swedish blodtörstig (“bloodthristy”), Norwegian blodtørstig (“bloodthirsty”).
Etymology from Wiktionary, CC BY-SA 4.0.