Phineas And Ferb: Season 4, Episode 6

4 - 6:

The boys create Rutabega-themed vehicles when Candace is chosen to be Rutabega princess and gets to start the "Running of the Chinchillas." Across town, Doofenshmirtz plans to turn himself into a real live Kinderlumper to scare Roger into relinquishing control of the Tri-State Area over to him.