Premise: Phineas Flynn and his stepbrother, Ferb Fletcher, are determined to make every day of their summer vacation fun. They try building a full-scale roller coaster, becoming musicians, building a backyard beach, and traveling back in time to meet dinosaurs. Their family pet, Perry the Platypus, doubles as a secret agent and battles evil. Meanwhile, older sister Candace is tattling on them to Mom and Dad, though she can never seem to catch them in the act.
S03, E31 (First Aired: Jul. 21, 2012)
Doof transforms into a platypus to beat Perry, but finds it's harder than he thought.
S03, E35 (First Aired: Oct. 26, 2012)
Phineas and Ferb discover a strange planet is hurtling directly towards Danville; one of Dr. Doofenshmirtz's ``-inators'' zaps both him and Agent P into the middle of nowhere.