Petuni

"OK big brother! I'll be waiting."

- Petuni

Petuni is Punio's little sister in Paper Mario: The Thousand-Year Door. She eventually needs rescuing from Punio and Mario and can be easily rescued with a key, then she will proceed with giving Punio a Dried Shroom (originally an ordinary Mushroom). She had been saving to give to him as a present him. Other than that, she hasn't the most activity within the game, but plays a fair part of importance to Punio's well-being.

Mario can play "stump Petuni." Say "Mario likes which person the most?" She will say Princess Peach and will give the plumber a Mystic Egg. If Mario asks her any other question she will not know the answer.

Petuni participates in the "101 Puni group" that helps Mario through the Great Tree, though she cannot always be seen in the group for an unknown reason or glitch.

Petuni appears at the game's end where she along with Punio gives Mario and Peach mushrooms.

Field Tattle
"That's Punio's sister, Petuni. She really cares about her brother. I mean, you can just FEEL her love for him! I feel totally awful that's she's all trapped in here. Let's hurry up and help her and the rest of them, OK?"

- Goombella

Field Tattle (When Trapped for the Second Time)
"That's Petuni, Punio's sister. She really trusts her brother. Let's hurry up and get her out of here. Oh and all of the others too."

- Goombella

Trivia

 * Petuni's name is a portmanteau of "Puni" and "petunia", a type of flower not to be confused with the Petunia from Paper Mario.
 * A poster of Petuni can be found in Super Paper Mario.