She was way smaller than she is now! But she's had two forms before this, since pokémon can go through a thing called an evolution! She was called a bulbasaur first, then an ivysaur.

The big flower you saw on her back used to be closed up really tightly, and it was just green! I don't have any pictures 'less you want me to do a drawing on the journal, but when she was a bulbasaur I could pick her up in my arms. That's how much smaller she was!