"Knock knock." Manny the Headless Man-Horse clapped twice on the floor of Gyro's underwater lab deep underneath Scrooge McDuck's Money Bin in Duckburg.
"Knock knock."
"Intern." His tired boss carefully adjusted his glasses, not even bothering once to look up from his heavily thumb printed, not-Waddle brand tablet.
"Knock knock." Manny continued to clap on the floor, his stone cold expression never once leaving his granite callous face.
"Knock knock."
"Knock knock."
"KNOCK. KNOCK."
"Dr. Gearloose, I think Manny's trying to tell you something..." Fenton said.
"He's what?" Gyro finally looked up from his work.
"KNOCK. KNOCK."
"KNOCK. KNOCK."
"KNOCK. KNOCK."
"Tell me what? He's not saying anything! He's just- knocking!"
"Wait a minute Dr. Gearloose, listen..." Fenton put his right ear close to the floor and Manny's left back hoof.
"OOOOOH. He's not trying to say, knock knock." Fenton suddenly realized. "He's actually trying TO TRYING to say, knock knock."
"Knock knock?" Gyro simply asked.
"Knock knock." Manny simply replied.
"...Knock knock? That's- That's not- That's even a real sentence!" Gyro was already beginning to get annoyed. "Is this some kind of dummy joke you two?! Because I'm not laughing!"
"It's not a sentence. It's a joke starter. A knock knock joke." Fenton calmly began to explain to him. "You're supposed to ask, who's there, and then he tells you who's there. It's the simplest of jokes."
"YOU'RE THE SIMPLEST OF JOKES!" Gyro immediately yelled back in Fenton's now scared timid face.
"Knock knock."
Gyro only frowned in response while Fenton and Manny just stared speechlessly at him.
"...No."
...
"Alright! ALRIGHT! Fine." Gyro let out a heavily exhausted sigh of defeat.
"The day I ever had to lower myself to you subhuman simpleton dummies and your jokes." He cleared his throat and crossed his arms before standing in front of his towering tall, headless intern.
"Who's there?"
Manny waited a brief moment before the first clap.
"Jaun."
"...Jaun?"
"Jaun." He reaffirmed for his boss with another slow clap.
"Jaun? What's- What's a Jaun?" Gyro asked in a slowly building up ineffective nerd rage. He was genuinely clueless about all of this.
"I- I don't know any, JAUN! WHAT- WHAT KIND OF SICK JOKE IS THIS?! Jaun? JAUN? WHAT'S A- A JAUN?!"
"Dr. Gearloose, that's not how you're supposed to do the joke." Fenton told him. "You're supposed to say, Juan who?"
"Why?"
"Because that's part of the joke." Fenton replied.
It only took Gyro's brain a few seconds to process this. "Oh. Well, you just should have told me beforehand then." He crossed his arms at Manny again.
"Juan who?" He asked.
It was time, his moment had finally came. "Juan, who, stands out, on, the, balcony." Manny clapped in a slow rhythmic fashion.
...
"Ah ha. Ha ha. Ha ha. Ah ha ha ha ha!" Fenton began to laugh along with Manny while Gyro was once again left speechless and both terribly confused.
"I don't get it..."
"What?" Fenton asked.
"I don't get it." Gyro said.
"What?"
"I DON'T GET THE JOKE!"
"It's a meme." Fenton quickly explained to him.
"WHHAAAAT?!" Gyro's left eye began to twitch and tremble amongst his most inner rage.
"A popular meme. You know, memes."
"Don't you, DARE use that- that foul language around me!" Gyro ordered as he stood back in both fear and clear disgust.
"Do I? The brilliant, misunderstood, unfairly shunned by society, DR. GEARLOOSE, LOOK LIKE I UNDERSTAND, MEMES?!"
"Dr. Gearloose, it's just a joke. Don't you, understand jokes?" Fenton asked as gently as humanly possible.
"Of course I don't understand jokes! The same way I can't wrap my head around you!"
"OUCH." Manny clapped in utmost sympathy for him.
"...Dr. Gearloose, it's a reference to a meme. It makes a complete sense if you know it." Fenton said. "It's like if you were telling jokes about skeletons, then you would obviously be referencing Undertales."
"Underwhat?" Gyro quietly asked.
"Undertales." Fenton replied then slowly grew quieter than a mouse. "The- The popular- indie, game..."
"Enough! Don't you- DARE lecture me on- on any STUPID, feeble minded, pretentious, GAMES!"
"If you thought that I would ever, EVER, be part of your insignificant, DUMMY, GAMES, well." Gyro chuckled creepily and held his pointer finger to his forehead as his shiny thick glasses hid his eyes.
"Then you're gonna have a bad time..."
That's it!" Fenton finally reached his boldest conclusion.
"WHAT'S, IT?!"
"The famous quote from the end of the genocide run! You have played that game haven't you?" His heavily unpaid intern asked.
"NOOOooooOO!" Gyro wailed a mournful wail up at the ceiling in a fit of rage most fitting of his mad scientist loon of his truest calibiur.
"Dr., Gyro Gearloose, doesn't PLAY, GAAaaaaaMMES! HE DOESN'T! HE DOESN'T! HE DOESN'T! PLAY, GAAAAAHHHH! STUPID, WORTHLESS, PIECE OF- GaaaaaAAAAAHHHHH! Rrraaagghhhh!" He immediately went to biting, clawing, and throwing his tablet under his foot to destroy it.
In the simplest of terms: Gyro had lost it.
"What in the GREAT BLASTED blazes is going on here?!" Scrooge and Dewey quickly came down the elevator to see what all the commutation was about.
"Mr. McDuck!" Fenton dropped everything a ran up to greet him while Dewey just stated with wide concern in his eyes.
"Man, what's got him so worked up?" He asked.
"Oh uhhhh." Fenton sheepishly rubbed the back of his neck. "Manny uh, told him a joke. A knock knock joke."
...
"Must have been a really good joke. He's still laughing." The duckling watched on in awe as Gyro flipped a table over in a crazed cackling nervous breakdown as Manny watched over him in silence.
Suddenly, Dewey had an idea. "Let me try! Hey Uncle Scrooge, knock knock." He lightly knocked on his great uncle's head.
"Must we really, do this?" Scrooge already regretted asking.
"As your favorite, strikingly handsome nephew in blue, I'm both legally and ethically intitled to it. Knock knock, knock knock." He knocked on his head again.
Scrooge gave in. "Who's there?"
"Woo."
"Who?"
"Just say, Woo-who."
"...Woo-who?" Scrooge asked.
"No no. It's not, Woo-who." Dewey corrected him. "It's WOO-OO!"
...
"Woo-oo? What's Woo-oo?" Scrooge didn't quite seem to get the joke. "I don't know any, WOO-OO!"
"No no. It's not, Woo-oo. It's DEW-OO!" Dewey suddenly broke out in a fit of uncontrollable wheezing laughter on the floor.
Scrooge frowned, his was very much disappointed in himself and all of them.
"Donald's my favorite nephew now..."
"Ha ha ha ha!" Dewey continued to laugh. "Wait what?"
":O" Manny clapped in shock.
"Oh man..."