- Mario running around in his towel in the introduction.
- In the introduction, Mario, Luigi, and Bowser are ambushed by Cackletta. Bowser's response to this?
Bowser: You're the fiend who stole Peach's voice! How dare you pull off such a cool evil plan?
- Try flubbing the Bros. Attacks. The expressions are hilarious.
- Having the brother in back use the hammer or hand attacks before they learn the proper combo for them leads to a hilariously angry reaction from the brother in front.
- When Mario and Luigi attempt to enter Beanbean Castle for the first time, they get stopped by the guards, leading to this exchange:
Left Beanbean Castle Guard: Halt! You there! Halt! You can't just waltz on in here! The town has just been attacked! Which means the castle could be attacked at any moment! Lady Lima has instructed us not to allow anyone to enter the castle! Anyone whatsoever! Having said that, if you still wish to enter, you must explain your names and your motives!
*Mario says something*
Right Beanbean Castle Guard: WHAT??? You are the world-famous Mario!?!
*Luigi says something*
Right Beanbean Castle Guard: WHAT??? And you are the legendary Luigi!?!
Left Beanbean Castle Guard: Uh, Luigi who?!?
Right Beanbean Castle Guard: Shh! I have no idea...
*Luigi face faults*
Left Beanbean Castle Guard: If you really are the superstar Mario from the Mushroom Kingdom, then prove it!
Mario: Mmm-hmm. *jumps*
Right Beanbean Castle Guard: Th-That jump... No mistaking it!
Left Beanbean Castle Guard: Th-This guy is really Mario???
Right Beanbean Castle Guard: Shh! ...I can't be certain.
*Mario face faults*
Left Beanbean Castle Guard: Anyway... What business would the famous Mario and Lui-uh... other guy have in this castle?
*Mario and Luigi start talking*
Right Beanbean Castle Guard: Hmm! Ah! Ho ho! *jumps* Huhhh? Ohhhh! I see! Gotcha!
Left Beanbean Castle Guard: What do they want?
Right Beanbean Castle Guard: No clue...
*Mario and Luigi both face fault*
Left Beanbean Castle Guard: ...Enough! Regardless of all that nonsense, you may not enter! Now begone!
*Luigi presents Prince Peasley's rose*
Right Beanbean Castle Guard: *jumps* Prince Peasley's Rose! Are you friends of the prince?
Mario and Luigi: Mmm-hmm./Oh yeah!
Right Beanbean Castle Guard: Umm, listen, I think maybe we ought to let these guys inside!
Left Beanbean Castle Guard: Umm... OK. Taking into account that rose and your wacky story, we can allow you to enter!
Right Beanbean Castle Guard: That was one wacky story! Woo!
- After Mario gains the ability to be shrunken by Luigi smacking him over the head with a hammer, you can do the above to Mario and then attempt to perform a high jump. Naturally, since Mario is shrunken, this'll fail, but during the brief moment while Luigi is above of Mario's head, you can make him jump with the expected results. Not only is this hilarious in itself to begin with, but you can also keep juggling poor Luigi for as you like AND also get coins out of it for as long as Luigi has more than 1 HP left, which he keeps losing as his brother lovingly pounds the everloving crap out of his crotch hard enough to keep him suspended in midair.
- Luigi riding the Chuckola Reserve barrel, with Mario inside over water to Beanbean Castle, and then getting stopped by the castle guards again.
Left Beanbean Castle Guard: Hmmm!!! Well, look at this! A very Mario-esque fellow and a Loo...uh, some other guy!
*Luigi gets up and says something*
Right Beanbean Castle Guard: Whaaaaaaat?!?
Left Beanbean Castle Guard: What is it?
Right Beanbean Castle Guard: Mario's gut is filled to the brim with Chuckola Reserve? It's sloshing around his insides?!? Gross!
Left Beanbean Castle Guard: Th-That's terrible! And sort of disgusting! We must contact Lady Lima immediately!
Right Beanbean Castle Guard: Hmm! By the way... What's Chuckola Reserve?
Left Beanbean Castle Guard: Shh! I have no idea...
*Luigi face faults*
- Hermie III thinking that Mario is Santa Claus because of his mustache and red clothes.
- The whole sequence after Mario's consumed the Invincishroom. Luigi moving very slowly due to fear and being hypnotized into thinking that he's Mario in particular.
- When the Bros. are split up, if you look in the gear or status menu, instead of Mario and Luigi back to back, the brother you're playing as will instead be holding a picture of the missing bro.
- Any time Prince Peasley flicks his hair and blinds the entire screen save for himself.
- Toward the end of the game, Mario and company are attempting to rescue Peach from Bowletta. Fortunately, Toadsworth had packed an extra dress for Peach in case of Clothing Damage. Mario's solution? Dress Luigi as Peach, then attempt to pass him off as the "real" princess. Luigi goes the extra mile; he mimics Peach's voice with surprising accuracy, and even covers his face with his hands to hide his mustache...until he is in Bowletta's cruiser.
Bowletta: By the way, Princess...why are you covering your mouth with your hands?Fawful: Do you hide something?Bowletta fakes Luigi out, and Luigi uncovers his face.Bowletta: Fawful... Did you see that?Fawful: Yes. Mustache.Bowletta: Fawful...Fawful: Yes.Bowletta: ...Fire at will.