Underdog crashing into something at the end of almost every story.
All of Underdog's mistakes in the pilot episode, "Safe Waif". Thankfully, he does rescue the boy trapped in a bank vault in the end.
In part 4 of "The Big Shrink" after Simon is reminded that Cad's still bigger than him, the former squirts his Shrinking Water from his flower at the latter.
In part 4 of "Weathering the Storm", Underdog turns invisible on the moon and makes Cad attack Simon, and they both fight until Underdog tosses them at Simon's Weather Machine.
"The Phoney Booths":
Part 1 has the test Simon performs on a milkman with a Phoney Booth.
The first half of part 3 is rife with funny moments, from Simon and Cad's victory dance, to the ways Simon toys with the Phoney Boothcontrolled Underdog, to Underdog just saying, "I will do what Simon says".
In part 1, after a successful test of Simon's amnesia machine, Cad tells him that the instruction book says it won't work on people with hard heads, so Simon tests the machine on Cad. Sure enough, it doesn't affect him.
Cad: Didn't feel a thing.
In part 2, one of Simon's attempts to lure Underdog into a trap is robbing a toy store. When he and Cad arrive, a lady mistakes them for toys, and even tries to buy Simon as a present for her son, until he fires off his gun.
Later in part 2, after Underdog still doesn't show up and Cad wonders what he and Simon will do with the stolen toys, he starts banging a drum until Simon takes it and hits him on the head.
In part 3, there's the gag of Underdog regaining his memory whenever he hears his name, only for Simon to throw the Forget-Me-Net back on his head.
Also in part 3, while Underdog thinks he's "Apple Mary", whenever he saved the day, people started to compare "her" to Underdog, only to be prevented from saying his name.
In part 4, after Underdog catches Simon and Cad in the Forget-Me-Net and sets them down, there's this exchange:
Cad: Who are you, you funny-looking little monster?
Simon: And who are you, you big, dumb ox?
"Simon Says 'No Thanksgiving!'":
In part 1, after Simon explains his plan to take over the city with three planes, three tanks, and 12 soldiers, Cad expresses his doubts about the plan. After Simon says that he has a plan to ensure his success, Cad breaks the fourth wall when voicing his concern about Simon's potential humiliation.
Cad (looking at the camera): If his plan fails, he'll be the laughingstock of the whole city.
Part 3 has the dance Simon performs for the Indians and, when he claims the Pilgrims are attacking them, it takes three tries from Simon before Cad fires the hidden weapons from behind a tree.
Part 4 has the Thanksgiving Day parade returning right while Simon and Cad are in the middle of Main Street and it prevents them from reaching the siren and lockdown buttons on the lamppost on the other side.
Then there's the ending, which is a subversion of the usual ending:
Man 1: That's a plane!
Man 2: It's a bird!
Woman: It's a frog!
Man 1: A frog?
Underdog (in the air): Not plane, nor bird, nor even frog; it's not even little old me, Underdog. (chuckles as a bear-head balloon passes by) It's a balloon.
Part 2 of "The Tickle Feather Machine" has the montage of four tests Simon performs on Cad to see what condition could prevent people from voting, so the two criminals can vote Simon for dictator with no opposition. All four tests fail. To elaborate, the first three machines tested on Cad are all guns: the first one makes him sneeze nonstop, the second one makes him cry nonstop, and the third one makes his muscles so relaxed he can't stand up. Nonetheless, Cad still manages to reach the fake voting booth and pull the lever every time. The fourth item is a big machine with robotic arms that turns Cad upside down, and it throws him down so hard he bounces on his head until he lands in front of the booth and his foot pulls the lever by accident.
There's also the successful Tickle Feather Machine test afterwards, where said invention leaves Cad in a fit of hysterical laughter until Simon sucks the tickling feather back into the gun in part 3.
Part 1 of "The Big Dipper" involves the first three tests of the Big Dipper Machine and how it failed to suck up the water:
First the Big Dipper freezes the water poured on the floor, and as Cad notices this, he slips on the ice.
Next, the Big Dipper causes the water in a tub to boil. A bystander mistakes the steam for smoke and calls for firefighters, whom Simon soon tells to leave because there was no fire.
Then the Big Dipper pours more water into another full tub and floods the house.
"Simon Says 'Be My Valentine!'":
In part 3, there's the scene where Cad torments Underdog after the latter is turned into a life-sized valentine card with his image on it.
Part 4 has the fight Underdog has against Simon, Cad and two other crooks who worked with them in that story, which ends with Underdog pushing them all into the Valentine Vault and Sweet Polly Purebred pulling the switch, turning them all into life-sized images on valentine cards.
In part 1 of "The Vacuum Gun", when Simon first tells Cad that he's going to use the Vacuum Gun to "clean up the city"note gather an army of criminals with said invention, Cad's reply is as follows:
In part 4, after Electric Eel and Riff Raff say, "Roger, Simon. Over and out," the first response from Battyman is, "'Roger Simon'? Who's that?" before he catches on.
Part 4 of "The Flying Sorcerers" has the usual ending gag of Underdog crashing into something, with the twist that this time he's carrying Sweet Polly when it happens. The thing in question he crashes into being a cement mixer. When a drenched-in-cement Underdog emerges from the mixer, a similarly drenched Polly emerges as well and gives him a Death Glare as the episode ends.
For 2007 Live-Action film
The opening narration where Shoeshine describes his job as police bomb squad dog and states that he was a genuine success. Then in the middle of the mayor's speech, Shoeshine sets off an alarm and the cops open the crate to reveal... a piece of ham! Thus leaves him humiliated by the rest of the squad dogs.
Shoeshine: (narrating) All right, I'll be honest with you. I wasn't exactly the best dog on the force. In fact, I was probably the worst. The ham was just the latest of my mistakes. Like the time I chewed that extension cord and it was still plugged in. Or when I met that cute poodle and it turned out to be a guy. It's hard to feel destined for greatness when you keep messing up. But destiny's a funny thing. It'll creep up on you when you least expect it. (A tall thug grabs Shoeshine and carries him over to a big black van) Cad: Gotcha! Last one for tonight.
After Simon tells Cad about getting laughed at by the mayor:
Cad: Yeah, I know how that is. One time I wore my pants inside out, and nobody told me for the entire day.
When Barsinsiter prepares to use the serum on Shoeshine... when the dog sneezes on him.
Cad: Gross! Your mouth was open! (Barsinister wipes his face and glares at Cad) Barsinister: Just hold him!
As Dan leaves the house for work he tells an unwilling Jack to watch Shoeshine for him.