The Big Bang Theory is a popular sitcom from 2007-2019, starring actors such as Jim Parsons, Kaley Cuoco, and Johnny Galecki. The Big Bang Theory is a slice of life where science, geeky pop culture and hilarious mishaps rule the day. Around here, it pays to know molecular physics, Star Trek trivia, and the secrets to World of Warcraft.

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The long-running series has many colorful characters, recurring storylines, and even some hefty drama and heartbreak. Though, The Big Bang Theory is best defined by its thousands of great jokes and gags across 12 whole seasons, especially by Sheldon Cooper. But some Sheldon scenes in The Big Bang Theory stand out as the most creative, unpredictable and zaniest of them all.

10 When Sheldon & Leonard Awaited Their Future Selves

sheldon leonard sign agreement

A few flashback scenes in season 3 showed how Sheldon met Leonard for the first time. They first met in 2003, when Leonard moved into Sheldon's apartment, and Leonard had to deal with the notorious roommate agreement. It had a number of curious clauses in it.

The two of them agreed that if either of them invented time travel, they'd visit that very moment when the agreement was signed – Leonard and Sheldon actually looked around, expecting their future selves to stick to the contract. Sheldon was genuinely disappointed that his future self didn't follow through.

9 When Barry Kripke Pranked Sheldon With Helium

barry kripke

The real-life science of this prank is iffy at best, but it still made for a good joke in The Big Bang Theory. Sheldon had a long-standing rivalry with a fellow CalTech scientist named Barry Kripke. One day, Sheldon took part in a radio interview that Barry decided to sabotage.

Barry fed some helium into Sheldon's office and inhaling that helium distorted Sheldon's voice in a classic manner, embarrassing him on live radio. Sheldon, being a rather vengeful person, got revenge on Barry with an even more radical prank that went horribly wrong.

8 When Penny Gave Sheldon A Leonard Nimoy Napkin

sheldon napkin

In The Bath Item Gift Hypothesis, Penny had a great idea for a Christmas gift – a cloth napkin that the late Leonard Nimoy used while visiting the Cheesecake Factory. Penny asked Leonard Nimoy to sign it as a gift to Sheldon.

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Penny delivered the gift and Sheldon was dazzled, but not for the reason Penny expected. Sheldon claimed that since Leonard had wiped his mouth with the napkin, Sheldon now had a DNA sample of Mr. Nimoy, and could grow a clone of him for fun. Penny was a little weirded out by that idea.

7 When Sheldon Made X-Rated Jokes While Playing Catan

sheldon catan

Often, Sheldon is funny without realizing what he's doing, such as during an otherwise innocent game of Settlers of Catan. Sheldon kept referring to the lumber cards as "wood," and this led to more than a few unintended dirty jokes. Howard and Raj tried to hold in their laughter, but it wasn't easy. Big Bang Theory's Leonard had returned from a bad date and was in no mood for dirty Catan jokes.

6 When Sheldon Pretended To Get Attacked In A Portal

sheldon portal prank

Yet another fine Sheldon moment in Big Bang Theory arrived when Raj and Howard realized that Sheldon had a routine of entering a small, locked room at the same time every day. Raj and Howard tried to record what Sheldon was doing in there, only for Sheldon to prank them with the truth.

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Sheldon tricked his friends into thinking he had been attacked by a monster from beyond a space portal, and then Sheldon tossed the prop into plain view of Raj and Howard as they watched the footage on a laptop. In reality, Sheldon was practicing hacky sack in there, and didn't want to be interrupted.

5 When The Guys Pranked Sheldon On Halloween

sheldon halloween

Sheldon was working late in his office when he heard a strange voice call his name, and he wandered into hallway, only to run headfirst into a prank. The lighting became eerie, scary sounds played, and there was a bloody message on the wall. Then, a spooky skeleton rushed at him on a zipline.

The prank wasn't over yet, though. Raj and Howard tricked Sheldon into lowering his guard, and they adjourned to Sheldon's office, where Leonard waited with an alien mask. Once Sheldon saw it, he screamed in terror and collapsed, and thus, the prank was complete.

4 When Wil Wheaton Became Sheldon's Personal Khan

sheldon vs wil

In Big Bang Theory, Sheldon has plenty of enemies. One of them is Star Trek actor Wil Wheaton, who disappointed Sheldon by failing to arrive at a Star Trek convention back in 1995. Sheldon met Wil for real during a Mystic Warlords of Ka'a tournament at Stuart's comic shop, and Sheldon was about to win.

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Being the crafty sort, Wil fed Sheldon a lie about his dead grandmother, and Sheldon conceded the game out of respect. Wil smugly revealed the truth, and a furious Sheldon cried out "WHEATON", just like Captain James T. Kirk crying out "KHAN" in 1982's The Wrath of Khan.

3 When Amy Tricked Sheldon Into Spanking Her Seductively

amy spank

Another of Sheldon's comedic moments during The Big Bang Theory arrived when his girlfriend, Amy Farrah Fowler, tricked Sheldon into taking care of her while she was sick. Amy simply wanted the caring boyfriend experience, and soon came clean about it. Sheldon doesn't like being deceived.

Amy made lemonade out of lemons and offered to get spanked as a punishment, a deception that Sheldon fell for. Amy liked getting seductively spanked, and she actually put on romantic music to complete the scene. Sheldon had no idea he was giving Amy what she wanted.

2 When Sheldon Dreamed About The Time Machine & Morlocks

Sheldon imagines himself travelling through time the Big Bang Theory

Early in The Big Bang Theory, Sheldon and his three friends pooled their money to buy a replica of the colorful time machine from a classic sci-fi movie, and the four of them took turns having fun with it. Sheldon was particularly attached to it, and he started dreaming about it.

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In fact, Sheldon had a two-layer dream. He dreamed about getting attacked by Morlocks after the prop actually went through time, then 'woke up' to find Morlocks invading his apartment. He finally woke up for real, and shouted Leonard's name in rage.

1 When Sheldon Built A Virtual Presence Platform

sheldon bot

Sheldon soon became concerned that he might get ill or badly injured, and perish before he can realize his true potential in later decades. To solve this perceived problem, Sheldon holed up in his bedroom and linked up with a virtual presence platform, which includes a live-stream of his face, a set of wheels and a motor.

Penny dryly remarked that robot Sheldon was just like the real thing, and Sheldon took that as a genuine compliment. He had trouble getting into his office, which was a hassle, but then he happened to meet his personal hero, Steve Wozniak, at the Cheesecake Factory. "Woz" could hardly believe what he was seeing.

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