Super Mario 64 Halloween 2013: Luigi's Retarded Mansion is the 149th video made by SMG4, specially for Halloween 2013. It's his third Halloween Special video, and is named after the Luigi's Mansion video game series. In this episode, Mario mysteriously disappears, and Luigi has to find him.
It's time for halloween and the guys prepare. until something unexpecting happens,,, and its up to Luigi to do that heroic crap.
On Halloween, Lakitu asks Mario to get candy for the children from the basement. Two hours later, after Mario has still not returned Lakitu sends Luigi to check on Mario, which startles Luigi. Upon reaching the basement entrance, Luigi gets so scared he soils himself but decides to enter the basement.
However, he sees a Mr. I which causes him to freak out and end up being forced through four trials by a guy without facial features who resides in the basement. In the first trial, Luigi faces a man-eating piano. He burns it, but the piano screams as well as Luigi. In the second trial Dr. Eggman saves Luigi from being attacked by flying chairs. In the third, "Peach" is surrounded by skeletons suggesting it may be a trap. The skeletons come to life but, immediately after a Po (red Teletubby) drops out of the sky and starts shooting the skeletons then blows up. Peach runs to the Teletubby and Luigi is teleported back to the black room where he calls Toad for help, but Toad thinks it's the mental hospital and hangs up.
Then, Luigi is teleported to a girl who's "pet", Mario's decapitated head died. Luigi screams "HELP!" so many times he causes an error that offers a penguin, then chucks the little girl out of the window. After that Luigi cannot handle it anymore so the faceless guy offers him a deal; if Luigi stays the guy will let Mario go. However Luigi declines and the guy unleashes a horde of zombies which attack Weegee then go for Luigi, but Luigi "releases the rage" and kills the zombies then flies up to the roof to rescue his brother. He then does off-screen things to the faceless guy. Later, outside Peach's Castle, the guy gets revenge by blowing up Luigi and himself.
- After the time card, Lakitu ask Toad where is Mario and Toad tells him that he’s in the basement, but Lakitu is the one who told Mario to go in the basement.
- A scene similar to the one with Peach in this video has been seen in the more recent video "SM64 Guides: Toadsworth's How to - Princess".
- The phone call Luigi makes with Toad, is similar to one made in Family Guy, when Meg gets captured and the kidnapper is on the phone, what Peter says is actually not making the kidnappers scared, it sorta goes like this; "I don't know who you are, I don't know what you want, I only know I've got a particulary lack of skills, I'll never be able to find you....".
- When the boo goes for Luigi, the Surprise Buttsecks can be heard.
- This video is one of two videos with a title referencing the Luigi’s Mansion video game series. The other is Stupid Luigi's Mansion.