Idea by P1nkapple.
Here is a little context, sent by the requester:
"Shallistera's a very polite and friendly, but kind of timid girl who's had a very sheltered upbringing and has never seen the world outside her village before, so can be pretty naive and awkward around strangers, as well. Also, she's an alchemist (as is the other Shallie), but is still pretty unpractised at alchemy, so this is what I was thinking would transform her. Maybe she's trying to make a medicine, or something, and gathers the wrong ingredients. Accidentally getting an alchemical recipe wrong and creates a potion that she drinks, expecting it to cure a minor injury, or illness, but instead transforms her permanently into a huge grass-type Pokémon."

Hope you like it. She's a cute character, but her outfit is a hell to draw, so I'm sorry if I did some little minor mistakes with her costume^^

Shallistera is from the game Atelier Shallie.
Meganium is from the franchise Pokemon.