Charizard has always wanted to swell up with juice, but the only way was a rare fruit that permanently filled your body with juice. They thought it would be best to not find and eat one. One day, they happen to find one. Charizard held the berry thinking if they should eat it or not, knowing that there was no going back, but this might be the only time they actually find this fruit. Charizard then ate the fruit out of impulse, not wanting to waste this chance. Their belly quickly started to fill with juice, and it would quickly spread to the rest of their body. At first, they felt some regret, knowing that this was the smallest they were ever going to be again, but with their hand on their belly, feeling the growing juice inside of them, they quickly forgot about that fear. The swelling felt so good, and it was only getting better the bigger they got. Their fear quickly became excitement, as they were only hoping the swelling would not stop.

Probably badly written, but thought I would try.