Pippi is first mentioned by her mother. She says that Pippi went to the cemetery and hasn't come back. The mayor of Podunk says that Ninten rescuing Pippi will help secure him as the mayor, as the re-elections are coming up. Ninten has no choice but to go to the cemetery and find Pippi.
Pippi is found in a small pyramid-shaped hole in the ground. After following the flight of stairs, there are four coffins. One of them, the one at the very end, holds Pippi. After she is freed, she joins your team for a while. Until you bring her back home, she is part of your team.
The wonderful thing about Pippi is how fast her stats shoot up.