Phineas and Ferb Season 1 Episode 18 It's a Mud, Mud, Mud, Mud World ( Air Date 2008-02-24 ) Genre Animation, Comedy, Family, Sci-Fi & Fantasy category. 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.".