The Dread Pirate LeChuck is the perennial villain of the Monkey Island series of games. As the series progresses, Guybrush Threepwood (the hero) becomes more and more familiar with the villain, which is hardly surprising considering how strongly intertwined their lives become. LeChuck is based off of an amalgam of different pirates and pirate stereotypes, but the most strongly evident one is Blackbeard (Edward Teach). The name “LeChuck” comes from a man named Steve Arnold, then General Manager of LucasFilm Games, who repeatedly requested over the course of several years that Ron Gilbert put a character named “Chuck” in a game.*
As the first game (Secret of Monkey Island) opens, we learn that LeChuck was once the mightiest of pirates, and loved the Governor of Mêlée Island, Elaine Marley. Attempting to impress her, he sailed off to find the legendary Monkey Island, home to fabulous riches. Unfortunately for him, he and his crew of fearsome pirates were killed in a storm while attempting this. Unfortunately for everybody else involved in the series, he and his crew simply became ghost pirates and hid out beneath Monkey Island, eventually returning to Mêlée to kidnap Governor Marley and force her to wed him. He’s foiled at the last second by Guybrush, who destroys the pirate with voodoo root beer, saving his ghostly beard as proof that he did destroy LeChuck.
In the second game (LeChuck’s Revenge), Largo LaGrande, a henchman of LeChuck, recovers the beard from Guybrush and uses it to resurrect LeChuck, this time in creepy zombie form. Guybrush, not knowing this, makes his way to LeChuck’s fortress while searching for the treasure of Big Whoop. After more island-hopping, it’s revealed that LeChuck is actually simply Chuckie, Guybrush’s brother.
In the third game (Curse of Monkey Island), LeChuck returns as a demon who, having found Big Whoop and harnessed its power in addition, now has a mighty vendetta against Guybrush. This is not helped by Guybrush accidentally blowing up LeChuck’s new ship, or Elaine Marley declaring that she truly loves Guybrush. After another wacky adventure, LeChuck captures Guybrush, brings him to Monkey Island (where a theme park of the damned has been constructed on top of Big Whoop), imprisons him in a child’s body, and eventually is accidentally buried under a huge iceberg in the polar section of the Small World-knockoff ride underneath the amusement park.
Escape from Monkey Island, the fourth (and so far final) game in the series has a scheming Australian entrepreneur, Ozzie Mandrill, rescue LeChuck from beneath the ice in order to gain his trust as a possible business partner and help him re- (and possibly de-) moralize all of the pirates in the Caribbean. LeChuck successfully runs against Elaine Marley as Governor of Mêlée Island, strands Guybrush (once again) on Monkey Island, and sets about helping Ozzie in scrubbing the Caribbean free of the sorts of pirates who would oppose him. It turns out that Ozzie was controlling LeChuck all along, and once he is free from the grip of the Ultimate Insult (which is an item of unbelievable voodoo power), LeChuck attacks and destroys the Ultimate Insult, incinerating himself and Ozzie.
*After a conversation with Swap, it's come to my attention that it's likely that this is also the origin of Chuck the Plant of Maniac Mansion fame. Take this with a grain of salt, though, as it's uncorroborated as of yet.
Will LeChuck return? It’s almost inconceivable that he won’t. It’s public knowledge that there will (eventually) be a Monkey Island 5, and it just simply won’t be Monkey Island game without LeChuck, who is every bit as much a staple as Guybrush.