SuperMarioGlitchy4 Wiki
Not to be confused with Old Man Hobo.

Dr. Isaac Kleiner, also known as Dr. Kleiner, is a minor character in the SMG4 series.

He is a Caucasian-American old man scientist from Half-Life 2 and its episodes. He appeared in a few SuperMarioGlitchy4's videos released in the year 2014.

Physical Description

Dr. Kleiner is a rather tall old man, he has a gray hair and is partially bald. He wears a white shirt marked with the green word "dsb", dark jeans, black shoes and also black glasses. In the video "Ssenmodnar 6.64 (100k special QNA Edition)", his glasses have blue lenses, and in the episode "SwagQuest", he wears a brown hat after Luigi tells him he looks ridiculous (see below).


SM64: ṩṩἔᾗмὄḋᾗᾄʀ 6.64(100k special Qna Edition)

Dr. Kleiner in front of SMG4's computer in Ssenmodnar 6.64. His glasses have blue lenses.

This is Dr. Kleiner's first appearance in SMG4's bloopers, in this video he appears in the last skit of the video (#15) as a nerd who is revealed to have been watching the video up until this point, and says it really sucks, not knowing SMG4 is right behind him. Eventually, SMG4 gets pissed, and tosses the nerd out the window.

Super Mario 64 Bloopers: %99% Beroken

In this blooper, Kleiner makes a cameo appearance in Mario's mind, in which he's near a flying carpet, while Mario is on this last one and screams "What is happening?!".

Sonic the Derphog: Eggventure (GET IT!?)

In this other episode, Kleiner appears as a news reporter on "Humans News" on a large television to whom Sonic the Hedgehog is watching after this last one found it, in Human City. Kleiner reports that an alien (Dr. Eggman) has landed in Human City.

Super Mario 64 Bloopers: SwagQuest

Dr. Kleiner ready to fight Luigi in SwagQuest. He's wearing a brown hat after the green plumber tells him he looks ridiculous.

This is Kleiner's most prominent appearance in SMG4's videos. In this blooper, when Luigi is not allowed to go to Mario's party because he doesn't have enough swag, he seeks lessons from Bowser on how to obtain swag. After a few minutes in the lesson, Bowser tells Luigi to change his clothes, to add swag. After four clothes changes, Luigi and Bowser settle on a gangster costume. Then, Dr. Kleiner runs up to Luigi and slashes his clothes off with his crowbar, causing Bowser to force Luigi to fight Kleiner, stating that he "ruined Luigi's swag". Luigi is afraid at first, but gains the courage to the old man, telllling him "You look ridiculous". Kleiner then gets angry and Luigi starts rapping. The old man reminds him that this is a fight, and a short battle ensues. The old man strikes Luigi with a Smashball, who counterattacks with a "Big Gay Dance." Kleiner man then throws a fireball at Luigi, who ducks as it ricochets off a tree, blasting the old man into the air and causing him to crash into a boat, which sinks as Luigi does a short victory dance.

The Mario Channel: MARIOBUSTERS

Mario runs his over and tries to revive him with a 1-Up mushroom, but fails.

R64: Stupid Mario Kart

He appears in the retirement home, playing Chess with Old Man Hobo.


He freaks out when he sees Toadette in the air.

SMG4 Halloween 2017: Trick Or Treat Wars

Mario bites his hand while giving out candy.

SMG4: Stupid Mario World

In a brief cameo, he waves hello to Mario when he is flying on Yoshi before getting assaulted by Po.

SMG4: Mario University

He is a teacher at Mushroom University.

SMG4: If Mario was in... Deltarune

He is run over by Mario.

SMG4: Super Challenge 64

He is run over by Mario doing a challenge.

SMG4: Mario Gets【Woke】

He is Fishy Boopkins's therapist.

SMG4: Stupid Mario Golf

He picks up Jeeves Golf Cart with his Physics Gun, and also he plays Tennis at the Tennis Court against Matt in the Flashback

SMG4: If Mario Moves, He Dies

He is run over by Mario in a gurney.

SMG4: Uncanny Mr Mario

He appears as a mail man in the simulation.


  • His name is never mentionned in SMG4's bloopers, he's only referred as "Old Man" in the episode "SwagQuest".
  • He called Luigi a "Hippie" in the video "SwagQuest".
  • He's always carrying a crowbar, except when he's in fight with Luigi, still in the episode "SwagQuest".
  • Dr. Kleiner's model is used in another internet series, Elliot goes to School, as Mr. Higglesworth. On a related note, in his Ssenmodnar 6.64 appearance, he uses voice clips from Wesley/Xavier 3.10, a major character from Elliot goes to School.
  • Despite being old, he seems to have a lot of energy in SMG4's videos. In fact, several characters, often old, are apparently stronger in SMG4's bloopers than everywhere else, like Dumbledore from the Harry Potter series, who appeared in the video "Super Mario 64 Bloopers: Spells n' Wiztards" for example.

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