Randall Boggs

Randall Boggs is a disgraced ex-employee introduced in Kingdom Hearts III. He was formally a top scarer at Monsters, Incorporated, but was exiled by Mike Wazowski and James P. Sullivan for being involved in a conspiracy to collect screams by force. He has returned to Monstropolis with Vanitas's help, and is now seeking revenge. He originated from the Disney/Pixar film, 

Before Kingdom Hearts III
Randall was previously one of the top scarers from Monsters, Inc., with Boo as one of his target children. However, he tried to collect screams by force, and was punished by Mike and Sulley by being banished through a door that was immediately destroyed. The door led to a human trailer home, where he was mistaken for an alligator and barely escaped being killed.

Kingdom Hearts III
Eventually, Randall is found by Vanitas, who decided to exploit his ambition and desire for revenge. Vanitas fixed Randall's door, allowing him to return to Monsters, Inc. and attempt to reclaim his prior prestige. However, insisting that laugh power is unsustainable, he decided to exploit negative emotional energy and allied with Vanitas's Unversed to acquire it. With their help, he infiltrated the factory and weaponized its machinery.

Randall invisibly observes Sora and his friends as they discover the Unversed infestation and head to the Door Vault, and decides to follow them. Later, he uses his camouflage ability to disguise a door to the factory's booby-trapped basement as Boo's door, diverting the heroes. He gloats to them about his return and impending success, then vanishes as he waves away Sora's defiance.

After the heroes traversed through the factory, Randall accosts the group as they are leaving the factory floor and attempts to sic one of his machines on them. However, he storms off when it is unresponsive to his commands, only to spot Vanitas animating it as the Lump of Horror just after the heroes leave.

Pleased, he takes the Unversed with him to confront the heroes just as they reach the Door Vault. Delighted by Mike's ignorant dismissal of the threat, Randall gloats as the group is attacked by the massive Unversed. However, his happiness is short-lived and he is infuriated when the Unversed is destroyed. He is quickly subdued by Sulley and begrudgingly forced back through his door, where he is attacked once again by the humans on the other side. Before Sulley can destroy the door, Sora uses his Keyblade to lock the door, preventing it from being used again.

Appearance
Randall is a purple, lizard-like monster with green eyes. He has four arms, four legs, and a blue tail, and his "hair" consists of three pink protuberances on his head. Like in his film of origin, Randall is able to camouflage himself.

Personality
Irritable, deceptive, and competitive, Randall is driven by vengeance and self-aggrandizement. He readily dismisses the feasibility of positive emotional energy, deciding to believe instead that negative emotional energy, which he is more skilled at acquiring, is the best source of power.

Origin
Randall Boggs first appears as one of the antagonists of the 2001 Disney/Pixar film, Monsters, Inc., in which he is voiced by. He is one of the top scarers at Monsters, Inc. and vies with Sulley for first place. As part of a conspiracy with the company's CEO, Mr. Henry Waternoose, Randall constructs a mechanized "Scream Extractor" to use on one of his target children, Boo, in hopes of solving Monstropolis's energy crisis in exchange for prestige. Eventually, he was stopped by Mike, Sulley and Boo and banished through a door into the human world.

Randall later appeared in the film's 2013 prequel,  nicknamed "Randy", who was Mike's friend and roommate in college. Prior to being sneaky, evil, and impatient, he is nerdy, shy, and nervous.