Randall Boggs

Randall is an antagonist from Monstropolis in Kingdom Hearts III. He originated in the Disney/Pixar film 

He desires to get revenge on Sulley and Mike Wazowski for getting him fired from Monsters, Inc.

Kingdom Hearts III
Randall was previously a scarer from Monsters, Inc. who was banished into a door for trying to collect screams by force. At some point, Vanitas encountered Randall and manipulated his desire for revenge, and aided him in returning to Monstropolis by repairing the doorway he had been banished through so that he could harness the technology of Monsters Inc. to collect negative energy while also giving him an army of Unversed and Heartless.

After Mike, Sulley, Boo, Sora, Donald and Goofy hitch a ride on the doors from the Laugh Floor directly into the Door Vault, Randall while remaining invisible eavesdrop them and decides to follow them.

Later, when Sulley finds a door believing it's Boo's door, they enter inside, unaware that the flowers on the door were Randall's camouflage abiltiy and soon enters inside the door. After taking a wrong turn, Randall surprises them and reveals to them on he was brought back. He then plans to be top of the leaderboard by collecting "negative emotions" while allowing the Unversed and Heartless to get it for him. He believes that laughter isn't sustainable to produce more energy and believes that obtaining negative emotions, especially sadness will stick around longer, prompting Sora to argue back that he won't let him and the Unversed harm anyone. Randall then gloats that he would soon be a legend of this place while mocking them that their careers are "over" before disappearing. He then hijacks the lower factory while mocking the sixtet that they won't get out alive.

After traversing through the factory and defeating the Unversed the sixtet prepare to head out, but not before Randall appears behind them while also sending a weapon to take them out. After several attempts to make the weapon move Randall angrily storms offs calling it a "pile of junk". Sora tries to go after before being stopped by Sulley who assures him that Randall won't cause anymore trouble and that their focus is to get Boo to safety before heading out. Eventually, Vanitas appears and transforms the weapon into an Unversed called the Goop of Horror while Randall smiles evilly.

When the sixtet arrive at the door factory, Randall appears in front of them with the Goop of Horror. When Mike scoffs at Randall he approaches it before being warned by Sulley that something is different resulting in the Goop of Horror coming to life while Randall watches on. After the Goop of Horror's defeat, Randall scurries on the destroyed weapon and kicks it in frustration. Mike then notices the Banished Door that Randall came back from and through sign language tells Sulley to surprise attack Randall while he remains distracted. Sulley then surprises attacks Randall and surrenders. He then returns back to door he was banished from while Mike and Sulley mock him. He then swears his vengeance on the sixtet threatening to take over Monsters Incorporated while he enters back into the door only for him to be beaten up once again by the hillbilly family.

Before Sulley can destory the door, Sora intervenes and uses his Keyblade on the door to lock it resulting in the door vanishing and preventing Randall from coming back to Monstropolis again.

Vanitas would later mention Randall as a pawn consumed by his desire for revenge.

Appearance
Randall is a purple lizard-like monster with green eyes. He has two pairs of arms and two pairs of legs along with having three fronds with pink tips on top of his head, and a blue tail.

He also is an expert at camouflage and uses it to his advantage.

Personality
Randall is shown to be a short-tempered, greedy, sneaky and competitive monster in nature. In addition, he argues in his philosphy that laughter and postive emotions isn't enought to produce more energy and believes that obtaining negative emotions is the way to go.

Origin
Randall Boggs first appeared as an antagonist in the 2001 film Monsters, Inc., voiced by Steve Buscemi. He is a rival scarer at Monsters, Inc. with Sulley, but finds himself scoring less. Randall has constructed a "Scream Extractor", and tries to abduct a human child (Boo) as a conspiracy with the company's leader, Henry J. Waternoose, in order to gain company leadership.