Wheatley

"I am NOT! A! MORON!"

- Wheatley rejecting GLADoS' opinion on him. "I can't get over how small you are! But I'm huge! (Maniacal laugh) ... Actually, why do we have to leave right now?"

- Wheatley reveals his true nature. "Well, this is the part where he kills us"

- GLaDOS. "Hello, this is the part where I kill you."

- Wheatley.

Wheatley is the hidden main antagonist in the 2011 Valve video game Portal 2. He is voiced by Stephen Merchant who has also played Darren Lamb in Extras, Stuart Pritchard in Hello Ladies and Parris in Gnomeo and Juliet.

History
"All I wanted to do was to make everything better for me. All you had to do was to solve a couple of hundred simple tests, for a few years... and you couldn't even let me have that, could you?!"

- Wheatley during the final battle.

At the beginning of the game, Wheatley awakens Chell, who has been in stasis for several years, and tries to help her escape the Aperture Science facility, but is supposedly destroyed by GLaDOS when she is accidentally reactivated. However, he appears in hidden areas of the facility to Chell, and later helps her defeat GLaDOS by replacing her program in the main control system with himself.

But right when Wheatley is about to let Chell go free, he becomes corrupted and betrays her, accusing Chell for selfishly using him. He traps GLaDOS in a potato battery, and she recognizes his voice as a program the scientists once installed into her that gave her terrible ideas in an attempt to slow down her rise to power. Infuriated, Wheatley breaks the escape platform and throws them both into an extremely deep shaft leading to the lowest areas of the facility. As they fall, GLaDOS explains that Wheatley was designed by the scientists to always come up with bad ideas (in her own words, to be a "moron").

When Chell makes her way back to the main facility with GLaDOS, Wheatley has redesigned all the test chambers in his own image, combining the turrets and companion cubes into one and even changing the logo on the loading screen to "Wheatley Laboratories". However, as he is designed to make bad decisions, he has neglected to maintain the lab's failing systems, putting the facility at risk of a nuclear meltdown. When they encounter him on a screen, GLaDOS tries to stump Wheatley by saying a paradoxical statement ("This sentence is false"), but Wheatley ignores the error and goes with "true". Eventually they reach the main chamber again, where Wheatley states the facility is about to explode and he has been studying the final boss fight from the first game and has changed all the things that allowed GLaDOS to be defeated then. Despite this, Chell is still able to corrupt and replace his personality cores. She is about to press a button that will replace his program with GLaDOS when Wheatley reveals that he had booby-trapped the button and it explodes, injuring Chell. The facility is about to explode, causing panels to malfunction and disappear, like one which reveals the Moon in the sky. Chell shoots a portal up to the moon which sucks everything onto its surface, including herself. GLaDOS reaches out to get Wheatley out of Chell's hands and then she pulls Chell back inside.

After the credits, Wheatley is seen floating in space along with one of his personality cores, who is obsessed with space, where he laments his fate and says that he feels genuinely sorry for betraying Chell and wishing to have the chance to apologize to her.

In LEGO Dimensions
"Well as I don't really know how I got back here, what we should do is crack on with these tests and try and retake over the fac... I mean, escape... by that, what I mean is escape, just yeah, just escape, let's get going."

- Wheatley almost tells Chell his plan

Wheatley returns in the Portal 2 campaign as the deuteragonist. He first appears when he somehow spawns through a blue portal in a test chamber. He is also fitted with anti-gravity, making him able to fly around as he pleases. He claims to want to help Chell escape again, even though he obviously plans on taking over the facility. He seems to be much more antagonistic this time around, making arrogant comments and openly taunting GLaDOS. He does not act remorseful for what he's done previously. Instead, he goes on about how glad he is to be working together with Chell again.

Eventually, Chell and Wheatley fall into the depths of the facility when an elevator breaks. Wheatley attempts to use his anti-gravity to save himself, but it isn't enough. Chell doesn't catch Wheatley (much like the first game), and Wheatley sarcastically thanks her. When Wheatley realizes they're in old Aperture he panics, stating that it's full of vicious birds. Wheatley later apologizes for trying to bump Chell off when the elevator broke to save his own skin, and asks if they can be "BFFs".

After some testing they discover an elevator that Wheatley realizes he can power, much to his excitement. However, after failed attempts at plugging himself in, Chell slams him into the port, and the elevator goes up. They eventually confront a cheerful GLaDOS in her chamber. When GLaDOS reveals that the Space Core also showed up, Wheatley has a minor rant about how annoying he is which, ironically, is annoying enough for Chell to punch him. GLaDOS then starts pumping neurotoxin into the room.

Wheatley suggests that they repeat the old core transfer procedure by damaging GLaDOS and inserting the Space Core into her body. He's very satisfied when Chell manages to beat the other AI. Chell and Wheatley quickly put Space Core in charge of the facility, and the neurotoxin emitters are disabled. Afterwards, the duo enters a hidden room with a blue portal that takes them back to the hub world, thereby ending the campaign.

Quotes
"I AM NOT! A! MORON!"

- Wheatley's catchphrase "You know what? I think we're well past the point of tasteful restraint. So I'll tell you what happened to them: they died. Horrifically. They all died, horrifically. Trying to get that portal device that you're gripping in your meaty little fingers there."

- Wheatley revealing the fates of the previous test subjects he'd "helped" "And don't think I'm not onto you too, lady. You know what you are? Selfish. I've done nothing but sacrifice to get us here, but what have you sacrificed? Nothing. Zero. All you've done is boss me around, well now who's the boss...? Who's the boss? It's me."

- Wheatley trying to justify his betrayal "Am I being too vague? I despise you. I loathe you. You arrogant, smugly quiet, awful jumpsuited monster of a woman. You and your little potato friend... This place would have been a triumph if it wasn't for you!"

- Wheatley snapping during his final confrontation with Chell

Trivia

 * Wheatley appears in Team Fortress 2 (another Valve game) as a Sapper (Ap-Sap) for the Spy.