Back when I didn't know what shinies where, I KOed a Shiny Lunatone. Then I came across another normal one and I'm like "what the heck, didn't the last one have a different coloured eye?" So i googled it. Figured it was rare, so I said "aww crap."
But got a shiny Bibarel, Medicham and Starly... used to have a Shiny Zigzagoon.