- "Best one yet! Grandpa, I present to you... Tonally Transformative Elixir!"
- ― Penny, WarioWare Gold
WarioWare: Smooth Moves
Penny debuted in WarioWare: Smooth Moves. She is unlocked when completing Jimmy T.'s level along with Ashley and Red, and Dribble and Spitz. Her level is called "The Invent-Off". Her story starts with her attending the Diamond Academy, she faces off with Dr. Crygor to who is the best inventor. Penny pulled out her invention, Pocket Bike. However, Dr. Crygor was knocked down with whatever reason. Penny took Mike's microphones off and sang a song.
Her level features three forms, "The Finger Food", "The Mortar and Pestle" and "The Boxer".
In WarioWare Gold, she is in the last stage of the "Twist League". She is seen in the opening cutscene receiving a call from Wario, holding a large phone. Penny made "the best potion" called the Tonally Transformative Elixir, a way to become a famous pop-star singer. She tests it on Dr. Crygor to be her "Guinea Pig".The effects resulted the voice become slightly pitched higher, but even an intense stomachache; surprised, Penny screamed "GRANDPAAA!!". Fortunately, Penny has the Super-Special Tummy Tonic that will heal the stomachache. As Dr. Crygor sips it. The microgame gameplay starts.
Penny has "Twist" microgames and its microgames are "That's Life". After the microgame gameplay, Dr. Crygor confirms to Penny that he feels better, and comes to cnclusion to work n removing the stomach pains. He asks Penny when the effects will wear off, she does not answer but chuckles and disappears from the screen. It appears that the Tonally Transformative Elixir will not wear off soon anytime.