The star-nose mole is an endangered animal that Isabella and the Fireside Girls held a car wash fundraiser to help save. At the end of the day, the starnose mole gets enlarged to massive proportions by Dr. Doofenshmirtz's Mountain-Out-of-a-Molehill-Inator and tears from the ground with Phineas and Ferb's car wash they built. The mole ended up with a giant boot on containing Doofenshmirtz, while walking out off the beach. ("At the Car Wash")
For more information, see Star-nosed mole on Wikipedia.