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.
Willie has a keen sense of smell seen in Fun and Fancy Free, while trying to find Mickey, Donald, and Goofy by picking up their scent.
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.
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 land dried up, and the kingdom fell into despair. One night, peasant Mickey Mouse purchases three beans that are said to be magic. Overnight, 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 to his castle where they discover the captive harp.
Unfortunately, they are discovered by Willie by smell, who captures Mickey in his hand. Once he gets free, Mickey sees his chance when he spots a fly swatter. He tells Willie he knows of his magic and tells him to prove it by changing into a fly. Willie argues that he should turn into a pink bunny instead, but Mickey talks him into it - or so he thinks. As Willie performs the incantation, Mickey and friends rush for the swatter. Willie, however, turns into a pink bunny nonetheless and realizes what their plan is. He immediately catches all three of them and proceeds to lock them in a chest. Afterwards, the magic harp sings Willie to sleep, while subtly revealing where the key is. Mickey Mouse manages to swipe the key from his right pocket and free his friends and the harp. Willie awakens and pursues the heroes, breaking out of the castle and chasing Mickey through the undergrowth. Mickey's friends make it down the beanstalk, but Mickey is still evading Willie. Both of them proceed to climb down the beanstalk, Mickey landing just as Donald and Goofy begin chopping it down. Still high in the air, Willie falls down to the earth and though his death is not shown on-screen, he is declared to be dead by narrator Edgar Bergen, who is telling the story with his dummy, Mortimer Snerd. However, just as Bergen insists Willie was fictional, Willie lifts the roof of Bergen's house up asking if anyone has seen Mickey. Bergen faints in shock, and Snerd, while still shocked, says he thought Willie was fake. Denying this, Willie replaces the roof of the house and walks off into Los Angeles looking for Mickey, possibly for revenge.
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.
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.
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 their 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. However, in season 1, he was just called the giant.
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.