S2·E40 Whistler's Father, Part 4

Riff Raff disguises himself as a museum director and hangs a bag of birdseed with a hole in it on Underdog's back. The seeds leave a trail to Shoeshine Boy's apartment. Fortunately, Underdog is able to use his super-speed to fool them into thinking there are 2 different people, and Underdog takes them to the Garbage Bins on a Truck & then gives the man driving the truck to give them away with the rest of the trash & the painting was safe & people looked into the sky & said "It's a Plane," "It's a Bird," "It's a Frog.'" with Underdog saying his famous quote, before crashing into the painting.