Chow's personality is affected by two things; his insane life as a drug lord, mobster and international criminal, and his frequent and heavy abuse of multiple different drugs and copious amounts of alcohol.
Mr. Chow is very upbeat and outgoing. He likes to make new friends and is quite trustworthy. He goes out of his way to help his friends and is loyal and loving to those he considers close to him, although he can come across as belittling and offensive but it is all light hearted banter on his part. Chow's number one goal is to keep the party going, even if that involves illegal actions to fund it.
Even though Chow may come across as a crazy, erratic buzz junkie, there is more beneath the surface; Chow's mind is thinking up new tricks, he has street smarts and experience in "underworld" activities as well as links in all kinds of places. When you look past the loud, erratic, drug-fueled visage you realize that Leslie Chow is a highly intelligent, cunning, tenacious and merciless individual with very little remorse for those who cross him or who he screws over, the carnage and madness that transpires over the three films are amusing and "funny" to him but as Leslie says in his own words' "Nobody wants to see that, well, except me, but I was born bad."
The only things more important to Leslie Chow than the party, is loyalty and friendship, purely because he loves to share the party experience and making mad memories.
Chow is an international criminal, which is visualized in all films.
He is usually seen naked, accompanied by his pubic hair and extremely small penis - a running gag throughout the film series. Chow himself has also hinted that his testicles are small too.
Chow has attacked Phil, Stu, and Alan in all three films, minus Doug, having never actually met Doug until the end of Part III.
He became best friends with Alan premature to the second film and even stayed in contact with him when Chow was imprisoned in Thailand.
Chow loves to have a good time, and has frequently partied with the Wolfpack. Chow is considered a "cancer" by Phil since the Wolfpack always get involved with his criminal activities whenever they get in contact with Chow.
Chow was last seen appearing from a room in a Las Vegas suite, declaring that the Wolfpack had another "sick night" after Alan's wedding to Cassandra.
He wears women's shoes, as confirmed in the first film, being a women's size 6.
Chow made his first appearance in the first film after jumped out from the trunk of Sid's Mercedes naked and attacked Phil, Stu, and Alan with a crowbar. It is implied that Alan may have either had consensual sex with Chow or that he raped him, as a used condom with semen inside was found in the car along with Chow's shoe. Before he attacks him, Chow asks Alan "You wanna fuck on me?!", which could confirm that this did happen.
Later in the movie, Chow and his gang drive their SUV to hit the trio while stationary in their car. The car received substantial damage, with a strip club sign falling on it and damaging the soft-top roof, while damaging the door so badly that Stu had to be pulled from the car because the door wouldn't open, while Alan had to climb out the window. This was done to recover Chow's "purse" from the night before, when the trio were playing craps. Alan was on a winning streak, and Chow was betting on Alan, winning $80,000. However, he put the chips in the "purse" identical to Alan's, and the "purses" were unknowingly to both Chow and Alan. Chow revealed that he kidnapped Doug, and warned the trio to find the money, or Doug would be killed. He then leaves the trio, while saying "Toodaloo, motherfuckers!", a catchphrase he formed in the later films.
Since they couldn't find it, Phil, Stu and Alan use the latter's blackjack skill to gain the money, and head to the desert in order to make the exchange. However, it is revealed that he has kidnapped the wrong Doug, and instead kidnapped an African-American drug dealer named Doug, whom Alan had met on the first night in Las Vegas when Alan bought recreational drugs from on the first night in Las Vegas.
During the exchange, Chow confirms that he is Chinese.
Mr. Chow then takes off, telling them it was not his fault and insulted them as he left. He is seen in several photos during the end credits, where he was hanging out with the guys during their blackout.
The Hangover Part IIEdit
Chow returns in a much larger role, and becomes an supporting character to the protagonists', removing his status as the main antagonist.
Chow and Alan became friends prior to the second film, still keeping in contact after their last encounter in Vegas. He reunited with the Wolfpack after they wake up in Bangkok on the eve of Stu's wedding to his Thai girlfriend, Lauren Srisai, after partying all night along with Lauren's academic little brother, Teddy.
The trio then encounter a drug-dealing monkey, who they stole the previous night.
Alan and Stu, notice a weird mushroom-like thing poking out from under some covers. After seeing the monkey pull and lick on the thing, Phil notices and begins to ponder if it is a penis. Phil suspicions are confirmed, as the monkey smacks on it, alarming Chow who emerges from under the covers, angered and disgusted yelling "...tell that gay monkey to leave my shit alone!". As Alan greets and hugs him (with Chow's genitals still exposed), he affectionately refers to him as his "little hobo" (in a non-romantic way). It is revealed that he was a part of Alan, Phil, Stu, and Teddy's drunken night in Bangkok. The trio realize that Teddy is missing after a phone-call from Doug, who is still at the resort in Phuket, in the south of Thailand (while Bangkok is further north).
Before Chow explains what happened, he takes a huge sniff of cocaine while Phil tries to intervene, causing him to pass out unconscious and without a pulse. Believing that Chow died, the trio ditch his body in an ice freezer. Throughout their mission to find Teddy before the wedding, people constantly ask about Chow, namely Samir and Kingsley, because of Chow's debts to them. Kingsley demands Chow's bank information in exchange for Teddy, who he claims to have been holding for ransom.
The trio go back to search Chow's body, but when they open the ice freezer, Chow is alive and attacks them (mirroring the trunk scene). After calming Chow down and warming him up with a spicy noodle meal, the four go to capture the drug-dealing monkey who was taken from them earlier. The monkey, who's recognizes Alan, screams out for help to his owners. Chow takes off, speeding through the streets of Bangkok to safety. However, the monkey is accidentally shot and the guys are forced to leave the monkey at a veterinary hospital.
The men later meet with Kingsley at the Lebua Hotel, and Chow wires his debt to Kingsley over a computer transaction. It is realized to be sting operation after an attack helicopter is called up, and Kingsley reveals that he is an undercover Interpol agent named Detective-Inspector Peters. Samir, the gun dealer from the strip club, is revealed that he ratted-out on Chow as revenge for not paying him, after several failed transactions in the past. Angered, Chow spits in Samir's face, and is escorted away by the interpol and on his way out he yells out "Toodooloo, motherfuckers!", a line he previously used in the first film, and uses in the final film.
At the end of the film when the trio finally locate Teddy (who was trapped at the initial location, in the hotel elevator all day after a power-cut), they use Chow's speedboat - the "Perfect Life" - to get back to the resort where Stu has his wedding and gains the blessing of Lauren's father. Chow reappears during the slideshow in the credits where he is featured in almost every photo, showing the guys' reckless partying in Bangkok. It is revealed that he was going to shoot the monkey in the head, but he is stopped by Phil and Stu. The last photo is a group photo of Phil, Stu, Alan, and Chow (mirroring the final photo at the end of the original film, that had Phil, Stu, Alan, and Doug).
The Hangover Part IIIEdit
Chow has an even larger role, making him a main character.
After being arrested in Bangkok, Chow is incarcerated in a Thai prison, while continuing to keep in contact with Alan, sending him letters. The letters describe Chow's behavior in prison, revealing that he urinated on a prison guard, while Alan discusses a burger made available at McDonald's. Using a riot as cover, he escapes.
Chow sends Alan an email, and they set up a meeting in Tijuana, Mexico, after the trio are threatened by Marshall, a man from whom Chow stole $21 million in gold, accompanied by the drug-dealer Doug from the first film. At first, when Chow realizes that Alan came with Stu and Phil without telling him, he attack the latter two, throwing a rock at the windscreen of Phil's minivan. The four then go to a local barn where Stu and Phil attempt to drug Chow, spiking his drink with Demerol while Chow sing's Johnny Cash's "Hurt" on karaoke, but Chow notices and makes them confess why they want to drug him.
The trio reveal that they were working for Marshall, and were given the task to retrieve the stolen gold. Chow agrees to retake the gold from the basement of his Mexican villa, which was sold at an auction after Chow was arrested. Stu, Alan and Phil go with Chow and successfully retrieve the gold, but Chow double-crosses them, locking them in the basement, stealing Phil's car, and tripping the alarm. The trio are arrested, but are let go and are returned to the villa, only to discover that the house never belonged to Chow, but was Marshall's home, and the gold that was stolen there was the other half of the gold that Chow didn't steal beforehand.
Marshall orders them to find Chow again. They track Phil's cell phone, which is in the car, to Vegas, outside of a pawn shop. The pawn shop owner, Cassandra, tells them that Chow traded a gold brick for $18,000 when it was worth a lot more. The trio reunited with Jade (who Stu was briefly married to during their first trip to Vegas), and was their contact to find out that Chow is in the penthouse suite of Caesars Palace, having surrounded himself with drugs and prostitutes. When Phil and Alan confront Chow, he jumps from the casino and parachutes down to the strip, but lands on the the limo that Marshall had given them that Stu is driving, causing them to hit a fire hydrant and knocking Chow unconscious.
Stu takes Chow and puts him in the trunk of the limo. They take the gold and meet with Marshall. Marshall shoots the trunk of the limo, thinking that he has killed Chow. However, Alan had freed Chow from the trunk earlier, and Chow emerges from the limo and shoots Marshall and his henchmen, concluding with saying "Toodaloo, motherfuckers!", a line he used throughout the series. He offers Alan a bar of gold but he turns him down and heads home, saying he no longer wants to be friends with Chow due to Chow's bad influence on him. Chow, hurt and disappointed, sadly watches the Wolfpack leave.
Six months later, after Alan and Cassandra's wedding, Alan, Cassie, Doug, and Phil wake up in a trashed hotel room, hungover and confused. Stu awakens with breast implants, a running gag in the series where Stu wakes up with something happening to him the previous night. Alan remembers that the wedding cake was a gift from Chow, who emerges from the next room entirely naked, laughing and holding a katana blade, declaring that they had another "sick night".
It's likely that at some point after this Chow eventually repairs his friendship with the Wolfpack and rebuilds his criminal empire using Marshall's gold.
- Trapped in the trunk of a car for several hours without food or water (although was relatively unharmed)
- Involved in an intentional car accident
- Genitals slapped by The Monkey
- Heart stopped after snorting cocaine (but remained alive)
- Smashed head on a glass table
- Left trapped and exposed to extreme cold for nearly a day by being locked in an ice freezer
- Getting Arrested
- Fell off the top of a limo
- Hit head against a fire hydrant
- "So long, gayboys!"
- "You wanna make fuck on me?!"
- "Toodaloo, motherfuckers!"
- "It's funny because he's fat!"
- "Not so good now. Quid pro quo, douche bag."
- "Oh, okay. I'll take him back. Um, right after you suck on these little Chinese nuts?"
- "Funny fat guy fall on face!"
- "I shoot him then I shoot all you motherfuckers and then we take it...your choice bitches."
- "We had a sick night, bitches!"
- "Hold on, gay boys!"
- Come on, Stu! It uses this Jew big head!
- No! Kingsley? you fucking 5-0
- "I'm an international criminal, it always end like this."
- "Sorry, Stu, my bad."
- "Alan called me a few days ago and invited me to wedding."
- "How the fuck? Samir, you fuck me over for six grand! You camel jockey!"
- "Principle? Nigga please! we are both dead inside!"
- "I have SUCH an erection right now!"
- "Don't worry, I got this shit."
- "Oh, your having a bad day? Did you die? (Phil: I got shot) "But did you die?"
- "Oh You never do blow before,sometimes your heart stop,start up again. Read a book".
- "Suck it bitches!"
- "They angry, all I feed them is cocaine... and chicken!
- "Quick give me some sugar"
- "You know fucking, doing blow, same old, same old, oh I also got into cock-fighting"
- "I can't feel my nuts, can you rub them to make sure they ok?"
- "We had a sick night, bitches!"
- "Whoo-hoo! Whoo! Hahaha! I LOVE COCAINE!"
- "Whoa so beautiful...I believe I can fly, I believe I can touch the sky, I think about it every night and day..."
- (Phil: He's out of his fucking mind.) I'M OUT OF MY FUCKING MIND!
- "Nothing has Chow... I'm invisible"
- "(Phil: Get down from there before you die!)Die...How do you kill what's already dead? *Gives Phil the double middle finger.*"
- "Hey check this out!"
- "You cold as ice Alan."
- "What up Doug? We don't get to spend enough time together."
- "You gave Chow a fighting chance...That's all Chow ever needs..."
- We had a sick night, bitches!