when he was a mere pichu he got in a chemical accident(like most super heroes we know) what happened was he mother, ryhorn, and his father, castaform, had a labratory. One day they were experimenting with some potions. Castaform was a making a potion called "the best pokemon in ash's party no matter what other pokemon he has like charizard etc. Well, he dropped it on pikachu, we don't know why we think that castaform was drunk.
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