Undead throughout the series, LeChuck has a different form in each game (evil-ghost-pirate, evil-zombie-pirate, evil-undead-demon-zombie-ghost-pirate and stone giant), and in the fourth and latest game he could transform at will between the three forms (including an illusory normal human form). Like many villains, he is in love with the heroine, in this case Elaine Marley, and has gone to great lengths to force her to marry him.
His victims included other pirates who were turned into skeletal ghosts and forced to join his crew. This made many pirates very reluctant to sail the seas. As LeChuck put it: "too afraid to take a bath!"
In the "new" version, a still-living LeChuck decided to win Elaine's affections by finding the legendary secret of Monkey Island. At the time, Elaine's own grandfather, known only as Captain Marley, was part of a group of four looking for a treasure called Big Whoop.
LeChuck was briefly stranded on Blood Island after a mysterious storm came and destroyed his ship, leaving his crew dead. At this time, Marley and his crew made port on Blood Island and LeChuck was able to get Rum Rogers, one of Marley's crew members, drunk enough to reveal that they had the map to Big Whoop. He was able to get a look at it and quickly made a copy for himself. LeChuck planned to beat Marley and his crew to the treasure and claim it for himself, but he would need to acquire another ship in order to have a chance at reaching the treasure first. He became engaged to local debutante Minnie "Stronnie" Goodsoup but only to obtain the rare diamond on her wedding band. LeChuck stole Minnie's diamond from the wedding ring on the eve of their wedding and sold it to some cutthroat smugglers on Skull Island in exchange for a new ship. Minnie was left standing at the altar, died of a broken heart a week later, and remained in the Goodsoup family tomb as a ghost, haunting it until she married someone else. LeChuck managed to reach Dinky Island (or possibly Monkey Island; the games are particularly vague on this point) ahead of Captain Marley and uncovered Big Whoop. The evil pirate found, however, that Big Whoop was in fact a gateway to Hell, which transformed him into a ghost as he passed through it. The transformation also seemed to give special powers, including one that allows him to transform others into the undead.
Captain Marley and his crew (who arrived on the Island a half hour later) witnessed LeChuck pass through the portals of Big Whoop and fled the island in terror. In order to ensure that no one else would discover Big Whoop and go through its torture, Marley tore his map into four pieces and gave three of them to his crew mates, keeping one for himself. In case someone actually obtained all four pieces, they made a chest containing an E-Ticket (to pass as the treasure of Big Whoop) and buried it at the entrance to the tunnels that connect Dinky Island to Monkey Island and ultimately Big Whoop. To go along with this they invented a story of a great shipwreck that left no survivors except themselves and swam ashore to an island where they found Big Whoop, hoping that people would believe all of this and never find out the true treasure of Big Whoop and its power.
LeChuck, on the other hand, thought that the powers he obtained through Big Whoop would enable him to carry out his most sinister plans. Along with great strength, the ability to disguise himself as a human and a form of immortality, he could use Big Whoop to create a vast army of undead soldiers to do his bidding. He also intended to use it on Elaine to turn her into his undead bride. One of his plans involved building a theme park named after Big Whoop and one ride, a roller coaster, went straight into the depths of the portal, transforming all passengers into skeletal soldiers.
To ensure that no one else would find Big Whoop, he killed the other three members of Marley's crew and the captain himself. He found out that Rapp Scallion the cook had a habit of leaving his gas burners on in his shack on Scabb island, and sent a fully lit cake to him. The flames from the candles went to the burners and the cook exploded along with his shack, leaving only his ashes. The shack was apparently reconstructed in his memory later and his ashes were locked in a crypt in the cemetery on Scabb Island. His piece of the map to Big Whoop somehow survived and was locked in with him. Rum Rogers Senior was taking a bath in his cabin on Phatt Island while drinking rum and eating toast, when LeChuck broke in and pushed the toaster into the bathtub. His son, Rum Rogers Junior, obtained the map piece, and kept it near his father's corpse in the bathtub. Young Lindy the Cabin boy could not bear living in fear and so found LeChuck and begged for mercy. LeChuck let him live and gave him a fortune, which he used to build a successful advertising firm. LeChuck later sent him an account that ruined Lindy's business, forcing him to sell everything he owned (including the map piece), join a circus, and die when he was shot from a cannon without a helmet. LeChuck ambushed Captain Marley while he was racing in the America's Cup and tortured him to insanity. He then sent Marley's ship into a whirlpool that "not even the most accomplished captain could escape". It seemed that before this, Marley gave Elaine Marley the map piece, as she had it at her mansion on Booty Island. With all known people with information of Big Whoop dead, LeChuck was ready to start his reign of terror of the Caribbean.
LeChuck captured a ship and murdered all the crewmembers aboard, then reanimated them as ghosts. With them under his complete control, he threw the Caribbean into the depths of terror. All ships he came across he would destroy and all people he would kill, sometimes turning them into his crew. He soon became infamous for his cruelty and was feared by all, especially the Pirate population.
These events made even the fearless pirates too afraid to sail the seas, and most of them abandoned looting and pillaging in favor of simply drinking their lives away. LeChuck was accumulating more wealth than any other pirate as he looted islands with little competition, and anyone who dared sail against him was quickly eliminated. With his fortune, LeChuck constructed a fortress to serve as a base of operations for keeping his loot, imprisoning and torturing people, and where he could store his corpse for resurrection in case his ghost form was destroyed (which is how the first game ends). He entrusted his corpse and fortress to his voodoo priest and Largo LaGrande, one of his original followers.
LeChuck also had other allies that helped him find alternative methods to obtain power and complete his control over the Caribbean, such as Ozzie Mandrill who rescued LeChuck after his defeat in the third game.
In the start of the game LeChuck, his ship, and crew are anchored in the gates of Big Whoop. LeChuck is almost all set to kidnap Elaine when his first mate, Bob, arrives and informs him of a pirate wannabe that has arrived on Melee Island. LeChuck goes to the island disguised as a sheriff and attempts to get rid of Guybrush Threepwood. At first he just tries to scare Guybrush off the island by saying that the island is extremely dangerous. When that didn't work, he fought Guybrush while he tried to take Elaine's idol to pass the pirate exam. He takes Guybrush's sword, ties him to the idol, and then throws him into the ocean. Guybrush is able to easily escape and complete the trials that will enable him to become a pirate. Thinking Guybrush to be dead, LeChuck raids the island, kills all remaining pirates and kidnaps Elaine.
Unfortunately for him, Guybrush gets a crew, ship, and finds Monkey Island. He is able to obtain a special voodoo root that LeChuck stole from the cannibals as it can be used to create the only thing that can destroy him, root beer. LeChuck leaves and seizes control of Melee Island where he sets up the wedding. Guybrush arrives and destroys most of his ghost crew and it is then revealed that Elaine actually escaped and that the bride was actually two monkeys in a bride's outfit. She was also able to conjure her own root beer, but Guybrush ruined the plan. After much confusion, Guybrush sprays LeChuck with root beer, which destroys him and scatters his ghost to the Caribbean winds.
LeChuck's former right-hand man, Largo LaGrande, resurrected the pirate as a zombie after stealing his living beard from Guybrush. Slightly less interested in Elaine, LeChuck instead focuses his attention on exacting revenge on Guybrush Threepwood. He quickly resumes his reign of terror and relentlessly attacks the Caribbean. This time however, his goal is to capture hundreds of people that are capable of constructing an amusement park that will in turn slaughter thousands and transform them into minions for LeChuck's new army. He eventually succeeds in this plot and enslaves them all and forces them to construct the carnival while they are slashing and burning acres of lumber on Monkey and Dinky Island. It seems for "fun", LeChuck would murder many of the workers by staging "construction accidents."
He sends Largo to find and capture Threepwood, who is looking for the four pieces of the map that will lead him to Big Whoop, while he instructs his voodoo priest to construct a very special doll, a voodoo doll of Guybrush. LeChuck is desperately trying to prevent Threepwood from finding the pieces of the map, afraid that Guybrush will learn all of the secrets and answers to the mystery of Big Whoop and ultimately LeChuck's origins. LeChuck even goes as far as putting a bounty on Guybrush and this causes some (in particular Governor Phatt) to attempt to capture Threepwood and hold him for LeChuck. Largo fails to find Threepwood despite the fact that he somehow has knowledge of him obtaining the map pieces.
LeChuck eventually lures Guybrush to his fortress by kidnapping his friend, Wally, (who was helping Guybrush decipher the map to Big Whoop) and having Guybrush retrieve the key to unlock Wally's cell, which in turn is a trap. He hung both Guybrush and Wally by their arms with chains and had them dangled over a pool of acid. LeChuck plans to have them fall in the acid until their skin burns off, so that he may then take the bones, reanimate them, and construct a chair. He would then sit on it every day and listen to their screams. LeChuck constructs an elaborate mechanism to lower them into the acid, but this gives Guybrush enough time to develop a way to escape. LeChuck's plans fail, his fortress is blown up during Guybrush's escape to Dinky Island. LeChuck survives the explosion but whether or not Largo survives is not revealed at this point in the game.
When LeChuck eventually catches up with Threepwood, he attempts to use a Voodoo doll to send him to Hell, but the doll proves defective, transporting him no further than a few rooms away. Threepwood eventually constructs a Voodoo doll of LeChuck and tears its leg off, causing LeChuck's leg to break off. Not to be defeated, LeChuck casts a hypnotic spell over Threepwood, claiming that they are brothers (in a parody of The Empire Strikes Back) and imprisoning him in "The Carnival of the Damned," a sinister amusement park. LeChuck also seems to cast a spell over himself to alter his appearance to match that of Guybrush's brother, Chucky. Whether Guybrush actually has a brother named Chucky or if he just thought he did due to the spell has not been explored further.
When Guybrush enters the carnival, he seems to be with his parents again. This is not what it appears, however, as his parents and everyone else in the park are skeletons in disguise working for LeChuck. LeChuck has finished his demonic carnival and many have already been claimed by Big Whoop and transformed into skeletons. Guybrush is eventually able to escape the spell and get out of the park alive. The ending of MI2 has been the subject of extensive debate among fans of the series; its ambiguity and surrealism have caused many arguments over what should be considered canon and what should not.
In retrospect, LeChuck may be said to have won in this game, as he succeeds in trapping Guybrush in his Carnival of the Damned.
In the third game's opening, LeChuck has resumed his psychotic courtship of Elaine by bombarding her fortress at Plunder Island with cannon fire. Many other ships seemed to have been destroyed by LeChuck, proving that his ship is near invincible. This is also shown by the fact that Elaine's cannon fire doesn't seem to leave even a scratch on the ship. The zombie pirate is either unaware or too busy to care that Guybrush has somehow escaped the Carnival; but Guybrush shows up again after some weeks at sea, having escaped LeChuck's evil amusement park. LeChuck has him captured and is about to kill him when Elaine, her musket, and keen eye interfere. LeChuck has Guybrush thrown in the hold and intends to torture and kill him once his plans for Plunder Island and its governor are complete. He prepares an invasion force, which is dispatched in rowboats while he constructs a powerful voodoo cannonball.
Unfortunately for LeChuck, Guybrush is able to gain control of the cannon in the hold and destroy the invasion force. This is mostly due to the fact that the pirate in charge of guarding Guybrush is his friend Wally, who apparently survived the explosion that destroyed LeChucks' fortress. It seems that LeChuck had been able to brainwash Wally into joining his crew, but this later proves to be his undoing as Wally grows soft and admits he is not suited to piracy. He goes into a crying frenzy, no longer caring what Guybrush does to escape and disrupt LeChuck's plans. Guybrush is able to escape by cutting loose a cannon; the recoil from the weapon as Guybrush fires it blasts him into the cargo hold and shakes the ship, which in turn causes LeChuck to drop the voodoo cannonball. The weapon explodes, destroying both LeChuck's ship and his reanimated form. The arcane magic released in the destruction, however, transformed him into a demon pirate with a fiery beard, more powerful than ever.
LeChuck returns to his carnival and quickly puts it back into operation. He is able to rebuild his army again and once again sends it to attack, sack, and loot the Caribbean until Elaine is found. He has grown desperate and is willing to "burn every island in the Caribbean" to find his love, Elaine, and archenemy, Guybrush. His forces attack Plunder Island again and capture Wally, who had been residing on the island at the time. LeChuck puts him in a situation that is almost exactly the same as that in the second game in which Wally is being hung over a pit of acid. LeChuck is able to finally learn of the location of Blood Island.
CMI was the first game to significantly alter LeChuck's past. In an effort to explain the strange ending of MI2, Big Whoop was revealed as an opening to Hell. LeChuck kidnaps both Elaine and Guybrush, intending to transform them both into undead creatures: Elaine as LeChuck's bride and Guybrush as a soldier under his command. LeChuck also reveals his history, his past plans and schemes, and what really happened on Monkey Island at the end of the second game. Once again, LeChuck does not kill Guybrush but puts the same spell on him as in the second game in which Guybrush is turned into a child. The pirate wannabe is able to create a remedy to the spell and returns back to normal. Again, the object of LeChuck's affections, Elaine, escapes his clutches easily while the half-witted Guybrush manages to bury him beneath a mountain of snow and ice in his own carnival. (A scene in the game's closing credits depicts a father telling his son that the park's founder is frozen deep underground; this is a joking reference to the urban legend that Walt Disney is cryonically frozen somewhere beneath one of his theme parks.)
As villains do, LeChuck turns up once more in the fourth game: a newly introduced ally rescued him from the large pile of snow under which he had been buried at the end of CMI. This new confederate is Ozzie Mandrill, an unpleasant, diminutive Australian developer with an intense hatred of pirates. LeChuck and Ozzie make their plans to find the Ultimate Insult, a voodoo talisman of incredible power, capable of pulverizing a pirate’s spirit; the villains plan to obtain the Ultimate Insult and use its power to seize control of the Caribbean. More specifically, LeChuck intends to use the Ultimate Insult to defeat Threepwood and render Elaine his obedient bride.
After his return, LeChuck learns that the Gates to Big Whoop have been sealed up. He had mentioned in the Curse of Monkey Island that the Big Whoop's power source wouldn't last forever if used continuously. Since the carnival served no further purpose, he destroys it and makes his way to Melee Island. There, he transforms into a human and has Elaine declared dead, initiating a new election for the office of governor.
This is all part of his and Ozzie's plans to gentrify the pirate-infested Caribbean, and gain control over all the Caribbean. As Charles L. Charles, LeChuck runs for governor of the Tri-Island Area against Elaine. LeChuck's whole campaign is based on lies: He tells the pirates that they will have good times and free grog if they elect him. LeChuck hopes to win the election and gain total control over the island so that he may use it as a base of operations to construct the Insult Amplification Tower, a device Ozzie constructs to amplify the effects of the Ultimate Insult so every pirate in the Caribbean can simultaneously be exposed to its power.
Meanwhile, Ozzie uses his skills in insult swordfighting to seize control of pirate islands and transform them in his image while attempting to discover the secrets of the Ultimate Insult from the Marley Heirlooms, which have key items that can help assemble the pieces of the Ultimate Insult. LeChuck and Ozzie develop a way to obtain the Heirlooms and get rid of Guybrush. LeChuck has Elaine's mansion set up for demolition to get Guybrush to go to Lucre Island to obtain a deed for the mansion from the Marley Heirlooms in the 2nd Lucre Island Bank. It is on this island where Ozzie will play his part in the plan. LeChuck and Ozzie hire Pegnose Pete, a clever and cunning criminal, to work for them. Ozzie has him disguise himself as Guybrush and rob the bank while Guybrush is checking through the heirlooms in the vault. Pegnose steals the heirlooms and locks Guybrush in the vault. Guybrush is arrested and Ozzie learns the secrets of the Ultimate Insult.
Things don't go as planned. After Guybrush clears his name and again obtains the heirlooms along with the loot and the deed to the mansion, LeChuck and Ozzie go in a different direction. They let Guybrush find the pieces of the Ultimate Insult for them while LeChuck wins the election and gains control of the island. He enslaves all the people as Ozzie arrives on the Island with Pegnose to begin construction on the Amplification Tower.
When Guybrush arrives, they steal the Ultimate Insult from him and strand him on Monkey Island. LeChuck sends Pegnose to find Elaine, who had disappeared after LeChuck was elected governor. He forces the enslaved citizens of the island to construct a statue in his honor, which he plans to animate and use with the ultimate insult to spread his evil over the Caribbean. While Guybrush is on Monkey Island, it is revealed that LeChuck had his priest construct a church in his name so he can use it to marry Elaine. He even founded his own religion (despite the fact that he despises it and only stands for hell), which seems very similar to Satanism. The religion is devoted to worshipping LeChuck and all his evil. People who go to the church will usually be tortured and murdered.
LeChuck and Ozzie eventually find Elaine and are able to obtain the last piece of the Ultimate Insult. However, Guybrush and his partners are able to sabotage the amplification tower and Ozzie's attempt to expose every pirate to the Ultimate Insult fails. LeChuck becomes infuriated that their plans have failed and blames Ozzie, deciding to animate his statue to destroy him and all of the Caribbean.
Inevitably, Ozzie double-crosses LeChuck and enslaves him using the power of the Insult. Animating a huge statue of "Charles", Mandrill begins his assault on piracy until Guybrush defeats him using a giant monkey robot. The power of the Insult falters momentarily, releasing LeChuck; the understandably angry pirate crushes the traitor with the statue. The Ultimate Insult, which Ozzie had been holding, explodes and LeChuck is hurled to parts unknown.
Generally, his scheme includes building up his army while developing ways to accumulate power. His ruthlesness and disregard for human life cause other pirates shudder at the mere mention of his name. Despite his intellect, though, he is gullible, which often leads to his downfall. Elaine escapes him by saying she is "going to powder her nose".
While he shows little remorse or kindness, he claims to truly love Elaine. While he does not seem to care for her perspective, doing for her entirely what he wants, he is usually kind to her, and the two of them engage in some rather humorous conversations regarding their relationship. Regardless of his professions of love, Elaine's position as governor of the Tri-Islands is likely a factor.
LeChuck harbors an immense hatred for his nemesis Threepwood, who has (of course) always disrupted his plans and destroyed him. However, though LeChuck clearly despises Guybrush, he also seems to have a sort of fondness or respect for the young pirate. At different times in the games, LeChuck and Guybrush engage in humorous, childlike bickering, and their relationship sometimes mirrors that of siblings.
LeChuck seems constantly amazed that Guybrush escapes almost every situation despite the odds. He knows him to be a real threat and remarks that Guybrush is very clever, even referring to him as the "anti-LeChuck". He states that it was a mistake not to kill him. But, like most evil masterminds, LeChuck is arrogant and overconfident, and always seems to let Guybrush live, despite all the damage caused to his plans, apparently preferring the opportunity to gloat in victory over simply eliminating his enemy.
However, LeChuck can be destroyed by voodoo. In an ironic twist, often LeChuck either makes the voodoo weapons that destroy him, or else unintentionally gives the idea to Guybrush. On one occasion he isn't defeated by voodoo, but by a mountain of ice crashing down upon him. But, in the fourth game we find he wasn't really destroyed, only trapped in the ice.
LeChuck's voice was provided by Earl Boen in both The Curse of Monkey Island and Escape from Monkey Island. (The first two games did not feature character voices.)
Although CMI stated that LeChuck was permanently transformed into a ghost by passing through Big Whoop, he subsequently finds a way to change its effect. Later in the game, the portal seems to instantly convert full humans to animated skeletons.
Due to similarities in plot, it would seem that the writers of the Pirates of the Caribbean movies are fans of the Secret of Monkey Island; Ron Gilbert, in fact, openly stated that he believes this to be the case after seeing Dead Man's Chest.