My first shiny encounter was a Caterpie in...Silver? At the time I had no idea what the fuck it was, because it was before I even knew about the Red Gyarados(This was at/near release of the game, my first GBC game). So I had no idea what shinies were, I just saw the sparkles and went "cool" and killed it lol.
I then caught a zubat in Ruby, which was the first one I caught.
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