SMG4: Mario goes to DIDNEY WORL is a blooper by SMG4. It involves Mario, Toad, and SMG4 going to Didney Worl (parody of Walt Disney World) and looking to have fun, although the place is not what the trio thought it would be.
After finally arriving at DIDNEY WORL, Mario and the gang meet Mickey Mouse and soon realise that this place isn't exactly what they expected.
Following the events of Mario's Road Trip, the gang finally arrives at DIDNEY WORL. When going for the tickets, Bob reappears and starts irritating the gang before Demoman knocks him away and presents himself as the actual ticket guy. However, before SMG4 can pay, Mario wastes all of his coins from SMG4's wallet in a vending machine. Unable to afford the entry fee now, Mario goes crazy and tries to trade Toad instead. Unsuccessful, Mario lifts his friends into the park while Demoman calls security to go after the gang, as well as Bob. Mario is excited, while SMG4 and Toad fear the worst. The gang first heads to "The Big Spinner", with Mario appearing to be the only one who is actually enjoying it.
After this, Demoman summons Mickey Mouse to go after them as he imprisons an obnoxious Bob, though he actually seems to enjoy his cell. Mario, SMG4, and Toad then head to the "Bumper Cars". While getting in the line, however, Mickey spots the gang, but he is quickly distracted after Mario suggests that everyone do the conga line, thus making him and his friends, as well as Mickey, the first ones in the line. While on the attraction, Mario is again the only one who is enjoying the ride, while Mickey unsuccessfully attempts to capture them.
This pattern continues as the gang visits many attractions, including a roller coaster, death fall, ferris wheel, and the "Splash Mountain". Meanwhile, as Demoman is threatening Bob, Mickey comes back tired. Demoman asks if Mickey caught Mario , SMG4 and Toad and Mickey replies "I'm slowly dying on the inside". So Demoman thinks of a good idea to capture the gang. Before changing to the next scene, Bob breaks the fourth wall by asking the viewer if they can be his friend.
Having already visited everything, SMG4 tells Mario it's time to go. Mario suggests to stay playing in the bathroom, but SMG4 and Toad angrily try to force Mario out before Demoman appears and announces that a new spooky house ride [his evil plan] has been opened. Mario gets excited as SMG4 unsuccessfully tries to stop him, but Demoman convinces Mario to enter, and takes SMG4 and Toad with him. As the cart drifts away, Demoman starts to laugh maniacally.
While on the ride, nothing incredible seems to happen, until the cart goes past the exit and heads to "The Hall of Your Worst Nightmares". Everyone screams in surprise, as the worst nightmare of each is projected.
The first nightmare that is projected is Mario's : Luigi's dislike of spaghetti, followed by SMG4's: his first video, and finally Toad: his girlfriend, Toadette. After this, the ride stops and Mickey appears, who lunges at the gang and successfully captures them.
Mario, SMG4, and Toad are subsequently imprisoned and assigned as Bob's roommates. As they complain about their situation, Mario quickly thinks of a way to get money and avoid permanent incarceration: an attraction where people throw rocks at Bob in order to knock him down to the pool. The attraction proves successful, and Demoman frees the gang as he receives a lot of money. The blooper ends with Bob thinking that he has new friends, only for them to throw rocks at him.