Phineas and Ferb find a chameleon in the backyard, who grows to the size of a dinosaur, thanks to Doofenshmirtz's Gigant-Inator, and takes a walk through downtown. Meanwhile, Jeremy teaches a song to Doofenshmirtz, who plans to use it to summon aliens to do his bidding.
Steve the Chameleon arrives in the backyard.
Vanessa flirting with Jeremy
"It's no use. He moves too fast, maybe we should just give up."
"The day may come when we'll give up on fruitless searches after a mere eleven minutes..."
"But that day is not today!"
"The day may come when our favorite reptile may be lost from our memories..."
"And his enduring love of mushrooms forgotten..."
"But that day is not today!!!"
"Today we search! We will search for him in the streets! We will search for him in the trenches!"
"We will search for him in the alleys and the mini-malls and the cul-de-sacs of this fair land!"
"We will search for him in the multilevel car parks and municipal recreation facilities!"
"We small band of brothers..."
"And girl from across the street..."
"We shall not cease till he is found!"