SMG4 Halloween 2017 Trick Or Treat Wars is a blooper uploaded by SMG4 on October 28, 2017.
The video starts with SMG4 (dressed as a Frankenstein) going to the Mario Bros. house to go trick or treating. Luigi, dressed as Batman greets him, but SMG4 mistakes his costume for a trash bag, much to the former's annoyance. Mario then emerges dressed as a bowl of spaghetti (also mistaking Luigi's costume for a trash bag), and they're ready to go.
Afterwards, the trio arrive at Peach's castle, where Peach (dressed as a witch) greets them and compliments their costumes (again mistaking Luigi's for a trash bag). She then gives them candy, but when she gives her candy to Mario, he instead eats the candy and demands more, rather than putting it all in his bucket. Disgusted, Peach decides to give Luigi and SMG4 some extra candy, leaving Mario with nothing. SMG4 then starts mocking Mario for him being unable to get candy, much to the latter's fury and he challenges the youtuber to a competition to see who can get the most candy. He agrees and they both run off into the neighborhood, leaving Luigi behind.
The competition eventually starts heating, with Mario and SMG4 racing to get candy from other peoples' houses. While the candy competition is happening, Fishy Boopkins and Bob are struggling to get themselves some candy. The two eventually joined the competition after Mario and SMG4 beat up a man who refused to give the Garo and Spike some candy.
Later, as the competition gets more intense, SMG4 recruits four individuals to help him get as much candy as possible. Meanwhile, after witnessing the "meme man" and his candy heist, Mario teams up with Slenderman to take candy by scaring people. Subsequently, Bob and Fishy Boopkins have attempted to get candy through the use of a "free candy" trap, only for the former to be beaten up by a police officer in the process.
Fed up with nobody taking them seriously, Bob decides to rob people of their candy despite Boopkins telling him not to. Past a series of schemes to steal candy, the competition then ends with SMG4 with a giant truck full of candy, Mario with a yatch, Boopkins with a small cup (and he gets happy because at least he got a decent amount), and Bob getting beaten up and arrested by police officers for assault. Unfortunately, Toad comes in and seeing the candy, rapidly eats it, causing him to become fat. Angry, Mario and SMG4 kick him away, and instead decide to participate in a costume contest when Luigi informs them about one that happened to be held by Bowser that evening.
At his castle, Bowser is presenting the contestants of his costume contest, starting with Yoshi and Donkey Kong, and then an unintended showing from Waluigi in his taco costume. Subsequently, Mario and SMG4 crash into the party, each wanting to let its host know that their respective costume is better than the other's. Unfortunately, as they begin fighting on the stage, Bowser attempts to break up the brawl with his fire breath, which only starts a fire inside his castle. Although most of the guests are able to escape by running through the backstage exit, a piece of debris falls and blocks the doorway before Mario, SMG4, or Bowser can get out.
Now surrounded by fire, SMG4 believes that he would have to die in the blaze alongside Mario. Luckily, Luigi (who now accepts his "trash bag" identity) swoops in with his helicopter and lowers a rope to save the three from the burning building. When they all end up a safe distance from the inferno, Bowser cries about his gutted castle while SMG4 thanks Luigi for his "heroic" help. Suddenly, like the case with Batman, Luigi realizes that he must help some others when he sees his "trash" signal projected into the night sky. He jumps from the helicopter, only to hit an island in a lava sea (likely the one surrounding Bowser's castle).
Looking at Luigi from the helicopter, Mario then asks SMG4 and Bowser if they would like to continue trick-or-treating. The two respond "yes," just as the video ends.