- “For who ever heard of an operatic whale?”
- ―People dismissing claims of a whale that sings opera[src]
Willie was generally a normal whale except for the fact that he simply adored opera, and would sing for any sailors in earshot, leading to the investigations of just how this was possible. Most notably, Tetti-Tatti the Opera Director, who couldn't believe that a whale could actually sing Opera and decided that Willie must have swallowed an opera singer, taking a trio of tough sailors with him to try and rescue the Opera singers so they could perform for him.
Whitey, the seagull, took a newspaper to Willie, all the sea creatures excited for their talented friend as they believe he's going to be discovered and finally have his dream come true. Willie rushed out to meet the ship with Tetti-Tatti and sailors, singing for them and showing the true extents of his talents. The three sailors had no more interest in killing him, wanting to simply listen to him sing, while Tetti-Tatti became more and more frantic, believing that Willie had eaten three Opera singers due to Willie's ability to sing with multiple voices at once. The Sailors repeatedly wrestled Tetti-Tatti away from the harpoon and pin him to listen to Willie.
At first, it seemed that Tetti-Tetti was finally convinced, having become his manager (at one point playing the princess in Aida), but later it was revealed he shot Willie with the harpoon, causing him to leap away in the distance, causing the harpoon gun to break off the ship, until he finally died. Whitey mourned his friend, as Willie's spirit enters heaven. However, he was now able to sing with even more voices, performing for what was implied to be a packed audience, as the golden gates were closed with a sign which read "Sold Out", having realized his dream after all.
He appears to be very friendly, singing for not only sailors but for his ocean friends, the seals, and a seagull. He dreams of singing at the Met and becoming a famous opera star, showcasing his unmatched talent for the world to hear, performing all sorts of operas. He doesn't seem particularly interested in monetary compensation-he just wants to sing his whale-sized heart out for all to hear.
He's a whale-with all that comes with it! He has a huge squishy-looking body, massive head with comparatively small eyes and mouth, boasting a rather unique attribute-having three uvulas in his throat, which allows him to sing with three different voices, even forming different words and notes with each one, leading the Opera director to believe he has swallowed not one, but three opera singers.
Nelson Eddy narrates and performs all the voices in this segment. As Willie the Whale, Eddy sings all three male voices in the first part of the Sextet from Donizetti's opera, Lucia di Lammermoor. In the end, Willie is harpooned and killed, but the narrator softens the blow by telling the viewers that he sings on in heaven.
In the short "Relaxing with Von Drake" Willie makes a cameo when Von Drake helps Donald relax his ears with Willie singing "She'll Be Coming Round the Mountain", "I've Been Working on the Railroad', and "Oh Susanna".
Willie made a few appearances among the audience in the series.
One of them was in "Donald Wants to Fly", where he appeared with Whitey, another seagull, and Big Toot and Little Toot from the Little Toot segment of Melody Time during the episode's version of You Can Fly.
Another notable appearance was in "Halloween With Hades" when he was sitting with Willie the Giant when Hades walked by and greeted them. This confused the two, where Willie noted that Hades gives him "the willies".
Willie made a cameo appearance in the episode "O Sole Minnie".
Willie has only appeared on a poster in the queue for Mickey's Philharmagic as one of the previous shows to have been performed at the Fantasyland Concert Hall.
Development memos for Walt Disney World dated to Fall of 1971 show a loose outline for a never built "Willie the Whale Complex", an aquarium and marine mammal park which would incorporate animation into their shows in some capacity.