What's the difference between i.e. and e.g.?
c.1630, of obscure origin, perhaps from or relatred to Swedish dialect pyske "small fairy," but West County origin suggests ultimate source in Cornwall and thus something Celtic. Earliest references were in pixy-path "bewilderment," literally "path on which one is led astray by pixies," and pixie-led "lost."
in the folklore of southwestern England, tiny elflike spirit or mischievous fairy dressed in green who dances in the moonlight to the music of frogs and crickets. Its favourite pastimes are leading travelers astray and frightening young maidens. Pixies also delight in rapping on walls, blowing out candles, and playing in water. Pixies were first discussed at some length by Mrs. Anna Eliza Bray in The Borders of the Tamar and the Tavy, 3 vol. (1837)