Po was an experiment subject along with her friends — Tinky Winky, Dipsy, and Laa-Laa. She was tested in a futuristic house within a wild surface known as the Main Land and, just like her housemates, was not aware of her situation. One day, Po ate a Tubby Custard together with her friends, but the custard eaten by Tinky Winky caused him to have an unusual behaviour at night. After becoming a monster, the latter slaughtered his friends one by one, including Po.