Leslie Chow

Chow appears naked in the Mercedes trunk and attacks the trio with a crowbar. Later he rams their car with an Escalade and claims they kidnapped him and stole $80,000 in chips. He threatens to kill Doug unless he gets the money. The trio ends up trading the chips for a "Doug" who is someone else. In the end Doug admits the chips were Chow's all along and he had them. Before he appears, he's already the reason a gang is waiting for the trio outside the chapel, asking where "he" is. Only later does it click that the "he" was Chow himself, whom nobody knew was in the trunk.

Chow goes to Thailand because Alan invited him. When the three wake up he's already at the hotel and starts to tell the night, but passes out. Thinking he's dead, the friends hide him in an ice chest. Later he reappears, alive, and becomes a piece in a deal with a gangster. He ends up arrested by Interpol agents. In the home stretch, a gangster named Kingsley demands Chow's bank password in exchange for Teddy. The password is in the vest of Chow's monkey, which the trio steals back in a car chase. When Kingsley gets the code, Interpol agents show up and take Chow away.

Two years later, Chow breaks out of a Thai prison during a riot. He grabs half of a $42 million gold heist and tricks the trio into pulling the rest out of a house in Tijuana. The house belonged to another criminal. In Las Vegas he parachutes off Caesars Palace and ends up locked in a trunk, but Alan gives him a chance to escape, armed. Chow takes out the crime boss and spares the group, because Alan saved his life. He offers Alan a gold bar, and Alan turns it down. A gold bar is worth $400,000, but Chow sells it for $18,000 at a Las Vegas pawn shop. When the trio finds him, he's barricaded in the penthouse suite at Caesars Palace. Not even the parachute escape saves him: Stu locks him in the trunk of Marshall's limo, and it's Alan who helps him get out.

Ken Jeong trained as a doctor. He said the naked leap onto Bradley Cooper's neck wasn't in the script: the two of them improvised it, with the director's blessing.