If Mario was in Cuphead is a blooper created by SMG4 on October 14, 2017. This blooper is based on the 2017 game Cuphead by StudioMDHR.
Mario has to pay off his debt to Satan after losing at the casino. As a result, Mario is brought into the monster-filled world of Inkwell Isle, where he meets Cuphead and Mugman, who are more or less in the same boat as Mario.
The episode starts with Mario gambling at a casino where he has bet all his money but he still wants gamble, so he gambles his life insurance and gets snake eyes and loses, He then says that he'd do anything to just win, after saying that the devil appears who wants to raise the stakes, but Mario thinks about steaks instead. Mario throws the dice and gets snake eyes once again, the devil sends Mario to purgatory.
Cuphead and Mugman are walking to find Mario who has fallen from the sky. Cuphead mistakes Mario for a boss demon, Mario mentions the devil which they both recognize. Mugman points to a glow in the forest which Cuphead thinks it has to be one of the enemies. Mario follows the brothers to be attacked by two killer mushrooms which Cuphead shoots both mushrooms with Mario losing his head. Cuphead and Mugman then do a Run n' gun while Mario assaults a fish.
The brothers are then seen cornered by some piranha plants, Mario gets a piranha plant disguise which distracts the piranha so the brothers could shoot the piranhas, Mario gets hit by one of the piranha plants and his soul flies up but Cuphead parries his soul, saving Mario, After Mugman shoots a piranha plant, spiked vines start to appear from the ground and Cuphead and Mugman get trapped in the vines, Cagney Carnation appears and drags Mugman towards his mouth but Mario lands on Cagney naked and singing which knocks Cagney out and his contract appears. The trio continues their journey and finds a carnival.
Cuphead thinks there is another monster in the carnival but Mario finds an arcade and starts humping the arcade cabinets, after Mario is done looking at the silly mirrors the gang go outside to hear creepy laughter. Mario then gets run over by Motley in his bumper car, Cuphead and Mugman tries to shoot Motley but he dodges all of the bullets, Mario does a sneak attack and lands on his eyes causing him to crash, Motley then turns into his second form Motley Bossblob and attacks by speeding up the carousel which flings the horses that hit Mario, Cuphead now realising the bullets do nothing Mugman spots the carousel's control box which Cuphead tells Mario to go press it while they distract Motley, Mario attempts to get on the carousel but it was too fast forcing him to hold onto one of the poles, Motley seeing Mario near the control box starts to speed the carousel even faster, Cuphead tells Mugman to use his ultimate tornado slam to slow the carousel which he forgot about, after slowing the carousel Mario presses the button which knocks Motley out also revealing his contract too.
At a port Cuphead tells the group that he knows the fastest way to go see the Devil which is somewhere in the middle of the ocean so they use the planes. Concluding that Mario can't drive they instead tie him with a rope and put him on the plane's stabilizer. While in the air, Ariel appears from the water due to them invading her territory, she pulls a fish up and starts to shoot at the planes, the planes shoot back knocking the fish out of her hands which she then summons eels and fish to attack the planes, they fail and Ariel transforms into her second form, Mario starts to distract Cuphead when Ariel turns their plane into stone but Mario is not affected by this as he is already stoned Mugman not stoned throws a missile toward Ariel knocking her out, Mugman pulls up towards Mario and Cuphead still stoned and tells Mario to get in the back, Mario throws Cuphead onto the plane tail and jumps to the tail along with Cuphead's plane falling.
Mario then spots the portal to hell which Mugman does a loop and goes down with the plane along with Mario hanging on. As they fall, they hit "King Dice" with the plane and land. Mugman gets worried about Cuphead, which Mario tells him he'll be fine as he slaps Cuphead back to life. As they are looking for the Devil, Mario thinks he ran away, but the Devil then appears in his throne. Cuphead then tell him they got all his contracts, but then the Devil says he needs one more soul, which is Mario's. Cuphead then says that Mario is their friend, in which the Devil responds with that he'll take Cuphead and Mugman's. He starts with Mugman, but is stopped by Cuphead saying sorry to Mario as he charges his finger gun while the Devil laughs. But he then points it at the Devil and fires hitting the Devil in the face. Mugman jumps off the throne and Mario is seen doing a sneak attack landing on the Devil's face successfully distracting him, Cuphead then gets an idea to fuse with Mugman. He agrees and fuses making the super cup fusion and they tell Mario to use them. Mario aims the weapon towards the Devil and fires, killing the Devil too. Cuphead and Mugman unfuse and thank Mario for everything, while a light appears from above Mario is then seen floating up back at the casino.
He is then greeted by Luigi who wants to stay and play more which Mario replies with no and is seen running out, Meanwhile Smg4 is still seen near the arcade machine as he can't beat the game and is almost out of money and claims he'd do anything to win, then the Devil appears asking him if he wants to make a deal. SMG4 says "Yes!"
Extras (video by Theawesomario)
In the extras, Cuphead and Mugman are battling with Fishy Boopkins and Kermit, which makes a reference to Ribby And Croaks. Cuphead and Mugman were terrified, as we see Mario eating spaghetti. Then, he takes off his clothes (including his hat) and then goes in front of Kermit and Boopkins. They explode, and Mario proclaims that nobody can survive his nakedness. While Mario fought Goopy, it was a hard experience for a while. Then, Goopy tries to kill Mario, but it backfires. Goopy then gets mad and is shown wearing a boxing glove, and Mario and Goopy are shown running.