SM64 Bloopers: Luigi Labyrinth is the thirty-first episode of Season 5 and the two hundred and forty-sixth overall to be uploaded by SMG4.
This episode was aired on October 11, 2015.
The video starts with Mario, who comes out of his room naked, feeling angry. SMG4 asks him what he wants, and Mario answers by saying Luigi was supposed to be back in the castle five hours ago with his spaghetti. Mario quickly loses interest, though, and forcefully takes the TV from SMG4.
However, trying to find the Spaghetti Channel, he winds up instead with the news, which is about Toad, who evidently got sexually harassed in the rear end. Toad gives an emotional breakdown, until Weegee Doll launches an attack on the cameraman and the (assaulted) Toad, jump-scaring them and cutting off the signal. Mario starts to think Luigi is scaring people and goes outside. He is suddenly shocked and surprised at the sight of hundreds of aforementioned Weegee Dolls. Mario starts to walk when Weegee Doll blocks the way although it barely poses a threat as Mario merely kicks it aside.
Mario promptly gets a call on his phone, which he begrudgingly answers. The call is from Professor E. Gadd, who explains that the very unusual sight they've seen was from a direct result of a failed clone experiment. Fortunately, they're quite harmless except if they hug the victim. As if to prove his point, one of the Dolls suddenly gives Toad a hug and turns the latter into Weegee Doll. (While Mario and E. Gadd are talking, another Luigi doll is watching over Mario's shoulder). Mario asks why E. Gadd can't fix the problem himself to which he lies saying that he was in the middle of a very important experiment when he is actually taking a vacation on a secret island with anime characters. E. Gadd then tells him and SMG4 to go to the facility and find the source of the problem, otherwise, they will live in a world of only Luigis. After Mario shoves another Luigi Doll into the moat, he tells SMG4 that they need someone to help them remove all the Luigi Dolls. SMG4 agrees, and they go to the facility where all the Luigi Dolls are being created, but not before telling Peach Toadstool that they will be back to save her although it was already too late as she has been transformed as well.
Later on at Rogueport, Mario and SMG4 headed to the Luigi Doll source where they met a scientist who was grateful for them helping him resolve the problem. Despite Mario's complains about the small location, he was willing to help (although he got run over by a huge Luigi Doll stream). Soon, he and SMG4 were inside near the Luigi Club entrance when they encountered a Luigi Doll sentry who denied them entry, stating that only Luigis were allowed (and proceeded to taunt via twerking when Mario brought up the fact that he was brothers), only to be ruined when Mario punched through the glass ready to beat it up. Mario and SMG4 tear the place up and as a result, gain access to the Luigi club.
As they checked the club wondered who was running this place, a Luigi Doll invited Mario to join the Luigi dolls in the practice of the sexual-assault attacks. Mario didn't want to join them. Meanwhile, SMG4 found a Luigi doll bartender who showed them the boss of the Luigi dolls, Mr. L. He welcomed them to his lair while trying to hide the fact that he knew their name somehow. Naturally, Mario called Luigi out for his poor attempt and to yell at him about not getting him the spaghetti he asked for. Luigi was about to cry but then brushed it aside saying that he now has his own army. Despite SMG4 looking down on said army due to it being made of dolls of himself, Luigi ordered all of them to hug the two, forcing them to make a run for it (in this case with SMG4 using Mario as a battering ram). They soon found another room (a bathroom) and headed in there.
As they wondered what to do, Mario suggested lying down and crying. Suddenly, a survivor, Dr. Koops, came out of the bathroom stall he was hiding in, who was thankful to meet other survivors. As Mario was happy that there was something to eat, SMG4 rejects his idea and asked what happened. As Dr. Koops explained, Mario interrupted him (but was punched by SMG4). SMG4 then asked how to stop the creation of Luigi Dolls, which Dr. Koops replied by saying that the energy core must be destroyed even though that would blow up the building. Just as he finished, the Luigi Dolls burst the door open. Mario was shocked while SMG4 asked Dr. Koops what to do. Sadly, he was already transformed, as a Luigi doll snuck around them to give Dr. Koops a transformation hug. As they were surrounded, Mario and SMG4 were forced to escape via the toilet plumbing system. As they crawled through some pipes (where Mario farted, causing SMG4 to explode), they made their way to another part of the facility (although SMG4 somehow got Old Man Weegee attacking him).
In it, they saw a cloning machine, which Mario decides to use to clone his spaghetti. As SMG4 told him no due to a nearby sleeping Luigi Doll, he got pushed in to be cloned, creating someone. Then, the person revealed themselves to be SMG4's Minion and she was happy to be here. As they were all going the usual crazy antics, the Luigi Doll awoke, alerting them to stay still in the hopes of not being spotted. However, Mario farted, causing the Luigi Doll to alert the whole facility. Soon, a horde of Luigi Dolls came in to hug them. As they tried to escape from them, they threw random stuff (with Mario even throwing SMG4 at them) to no avail. Minion then had the idea of playing some nice music (Never Gonna Give You Up/Rick Roll) to distract them while they escaped. It worked but Mario changed it to a horrible sound of himself singing Let It Go. This enraged the Luigi Dolls and one chased after them as they entered the elevator (although in it, the Luigi Doll patiently waited until they all left before resuming the chase.)
As they kept running, the encountered a toxic sewage storage sector. Mario suddenly had an idea which worked (looking super scary, causing the Luigi Doll to fall backwards into the waste). As they celebrated (except for Minion who instead cried), the Luigi Doll returned (TURNED MUTATED) ready to kill them. As it flew after them, Minion saw some spare Luigi Doll parts and had all of them wear a Luigi Doll head (although Mario wore his upside down). The mutant Luigi Doll saw only Luigi Dolls somehow and apologized for chasing after them before leaving.
As they walked through the facility, Mario saw a bench and started sleeping on it. Turns out the room's floor could move and then, the floor opened up to the core, causing them to fall near it. Just then, they met Luigi again, where Luigi gave his backstory on how he became Mr. L (even though Mario didn't care).
In it, he was told to go through the clone machine prototype for peanut coupons. As Luigi was feeling scared, he held out a Captain Luigi doll, much to the horror of the scientists as they couldn't allow anything to be in the machine. As the process was completed, the doll became the Luigi Doll which hugged one of the scientists, turning him into the second Luigi Doll, and causing the other scientist to scream in fear. As Dr. Koops wondered what happened, he saw three Luigi Dolls, scaring him. Luigi saw this as a way to take over the world. Just as he finished, he saw SMG4 and Mario piling up the core with bombs, causing him to cry due to them not listening to his backstory.
Soon, Minion took out another Luigi Doll and slammed a rocket up its butt, surprising it, and flew away from the facility, bring Mario, SMG4, and Luigi with her. Eventually, it exploded (although a scene had a Luigi Doll thinking its companion farted, much to the latter's confusion). As SMG3 wondered if he should do something evil for today, he turned to see a flying Luigi Doll with the others on it, causing him to change his mind.
SMG4, Mario, Luigi, and Minion eventually landed back at the castle. They wondered what to do with all the Luigi Dolls but eventually, Minion opened up a Luigi Doll Shop to sell them. Mario though wanted someone buy his brother as payback for what happened in the episode.