Phineas and Ferb - Season 1 Episode 18 It's a Mud, Mud, Mud, Mud World There is no such thing as an ordinary day to Phineas and Ferb.
Overview: Phineas and Ferb create a monster truck for Candace to practice driving while Dr. Doofenshmirtz tries to find investors for his line of monster trucks that are actual monsters, with a trump card to take down the competition.