He was originally voiced by Billy Gilbert.
Willie is incredibly powerful, demonstrating amazing magic powers such as flight, invisibility, and metamorphosis. Despite this, he is very childish and not considered very bright, given his fondness for toys and inability to pronounce certain words, such as "pistachio." His favorite food is implied to be chocolate pot roast with pistachio, given his overweight appearance. He can also be very greedy and uncaring, such as when he stole the golden harp from Happy Valley and did not care that the land and the people were suffering. However, after the events of the film, he seems to have become more polite and humble. This is most noticeable in his later appearances.
Powers and abilities
Despite his childish mind, Willie is a surprisingly powerful user of magic, claiming all he needs to do is chant a spell "Fee-Fi-Fo-Fum", and he can change his size or appearance, fly, and become invisible. His very first appearance (as a semi-humanoid thunderstorm) indicates that he is more a force of nature than a being, explaining his somewhat abnormal playfulness.
But even aside from his magical powers, Willie is a powerful physical force because of his size and strength.
Still, Willie is not invincible. He has his weaknesses, one of which is implied that he is subject to the limitations of the forms he takes, such as when Mickey had planned to swat him when he'd tried to get Willie to turn himself into a fly. And, of course, Willie isn't all that smart, but he is able to realize when he's been tricked, or almost tricked, so he's not stupid.
However, in his later appearances, Willie has not demonstrated his powers, despite using Fee-Fi-Fo-Fum, implying that the magic he once had is gone. Whether or not this resulted from his defeat at Mickey's hands is unknown.
Fun and Fancy Free
In the segment, Willie kidnaps the beloved Golden Harp whose beautiful singing brings joy and peace to the kingdom she inhabits. After her kidnapping, the kingdom fell into despair. One night, peasant Mickey Mouse purchases three beans that are said to be magic. Over night, the beans grow into a beanstalk carrying Mickey and his friends Donald and Goofy, to the top of the clouds where Willie dwells. They make way for his castle where they discover the captive harp. Unfortunately, they are discovered by Willie who imprisons them and locks them in a chest. Mickey Mouse manages to swipe the key and free his friends and the harp. Willie awakens and pursues the heroes. Mickey and his friends make it down the beanstalk and quickly chops it down. Willie falls down to the earth and though his death is not shown, he is declared dead by narrator Edgar Bergen. However, just as Bergen insists Willie was fictional, Willie lifts the roof of Bergen's house up asking if anyone has seen Mickey. After Bergen faints in shock, Willie replaces the roof of the house and walks off into Los Angeles looking for Mickey, possibly for revenge.
Mickey's Christmas Carol
In the film, he is portrayed as the Ghost of Christmas Present. In this depiction, although still bumbling and lacking in intelligence, he is good. He shows Uncle Scrooge the meaning of generosity and warns that there may be trouble ahead for the Cratchit family, and ultimately Scrooge himself. He vanishes suddenly and completely, leaving only his giant footprints in the snow.
It should also be noted that originally, Present was actually going to be played by the Blue Fairy instead of him. In either case, Present is the only 'human' character in the film.
Who Framed Roger Rabbit
Willie can be spotted in a poster outside a movie theater in Toontown.
House of Mouse
Willie made several appearances in House of Mouse, usually as part one-line gags. In "House of Genius", Mickey was kicked into Willie's salad with the giant stating, "Duh, I asked for house dressing, not mouse dressing." In "House of Scrooge", Scrooge McDuck cuts back on food service in the club presenting a simple pea as Willie's evening meal, much to Willie's confusion. In "The Mouse Who Came to Dinner", Willie's amusement to the jokes on Mortimer Mouse has him accidentally slap him into a wall, although the audience was quite pleased by the action.
Mickey Mouse Clubhouse
Willie plays a recurring role in the series, now residing on a farm. He is first seen in the episode "Donald and the Beanstalk" where he trades three magic beans for Donald's beloved pet, Boo-Boo Chicken. Eventually, Donald regrets the trade and throws the beans in frustration. This creates the beanstalk. Mickey, Donald and Goofy climb it to find the barn on Willie the Giant, who they fear. They find Boo-Boo Chicken and begin to make there way back home. Willie follows behind to get the chicken back. Mickey decides to trade a stuffed bear for the chicken, which Willie happily accepts.
Willie would later show up regularly as a friend to Mickey. Despite his humbling persona, Pete still holds a great fear of Willie, unlike the rest of the clubhouse gang. He has also mentioned the fact that he has a mother and visits her often.
Once Upon a Time
The Giant appeared in Once Upon a Time, as Anton, played by one of the stars from Lost, Jorge Garcia. Prior to the curse, Anton resided in a realm of giants which could only be accessed through a large beanstalk. His brothers Abraham and Arlo referred to him as "Tiny" and often mocked his love for wanting to know more of the outside world. In retaliation, he journeyed down the beanstalk and befriended Prince James and his lover Jacqueline, also known as Jack, who give Anton a piece of mushroom from Wonderland that shrinks him to human size. Jack tells Anton that James' kingdom is on the verge of bankruptcy and needs money. Anton offers to give them treasure from his home, however, they betray him and lead an army to fight against the Giants, bringing death of all their kind except for Anton. He develops a hatred towards humans for what happened to his family.
Years later after The Evil Queen's curse is broken, Emma Swan and Captain Hook journey up the beanstalk to retrieve a magic compass. Emma Swan and Hook climb the beanstalk to get back the magic compass allowing them to return to Storybrooke, supposing that the Giants are switched, they are faced with Anton. He attempts to attack them, but Emma pleads with him that she needs the compass to get back to her son. He reluctantly gives the compass to Emma, stating that all humans are alike. However, Emma responds by stating that he is wrong to generalize.
He is later kidnapped by Hook and Cora back in Storybrooke and Captain Hook reveals that Cora shrunk Anton to bring him to the new land. Regina Mills restores his giant size, and he rampages through Storybrooke who uses him to terrorize the city and kill Snow White and Prince David whom Anton confuses with his twin brother. However, when the magic wears off, he falls into a pit; David rescues him, convincing him to trust them all. When the truth is restored, Anton takes a human size and is nicknamed Tiny and adopted as a brother by Grumpy and the other dwarfs, cultivating with them fields of magic beans Anton reveals to the group that he owns a magic bean and works with the Seven Dwarfs to harvest beans as portals until Regina destroys them at the time when Greg and Tamara have infiltrated Storybrooke..
Walt Disney Parks and Resorts
Willie makes an appearance in the Sir Mickey's shops in the Magic Kingdom and Disneyland Paris parks, lifting part of the roof and peeking inside. Willie also has his own spell card called "The Giant's Giant Stomp" in the attraction Sorcerers of the Magic Kingdom.