"It was Walpole." note The Extra History series on the South Sea Bubble made it sound like Robert Walpole was secretly pulling strings behind everything in the world at his time (which actually wasn't that far from the truth). Later episodes of Extra Credits often feature Walpole in The Cameo role. And when something just miraculously goes the way someone wants it to, such as Belisarius conquering of Rome, a picture of Walpole often shows up.
In a similar vein, "Bismarck had a plan. Bismarck always had a plan." note Otto von Bismarck was a Chessmaster almost on par with Walpole, and among other things, predicted that World War 1 would spark off 'some damned foolish thing in the Balkans' and his prediction of when was only off by four months.
"Why let X get in the way of a good crusade?" (X being a reason not to go on Crusade.)note The first Crusade is comprised of five armies led by five nobles to aid the Byzantine Emperor. Unfortunately, four out of five nobles had bad blood with the emperor in the past and would have made the crusade awkward, but pragmatism won the day and everyone choose to let bygone be bygone and went to fight for Byzantium.
From the Danelaw video: "And oh hey what up y'all it's GUTHRUM!" . When Danish king Guthrum barges in on the Anglo-Saxons at a Twelfth Night feast, after being presumed gotten rid of.
The first episode of the Curing Tuberculosis series had fans joke that Arthur Morgan could benefit from it.
From Samson & Delilah: [Person/People], being good, upstanding gentlemen, [do good deeds]... Oh wait, no they didn't! Instead, [do bad deeds].
"There you are, playing your X. When all of a sudden, you're a Y. You didn't ask for this. You didn't choose this."note Taken from the infamous "Stop Normalizing Nazis" video, and frequently used as snark material for how silly of an argument people saw it as.
Every time a horse shows up, they are shown in the most adorable derpy manner possible.
"But first...a SIDE TRIP!"note The Extra History series on Ibn Battuta had him constantly getting distracted from his main goal by going to other places, every time punctuated with this line.
"Because what Vlad Dracula's story needs is another Vlad."
