Tytlas next assignment was Stomboli, an explosive puppeteer and kidnapper in Pinocchio. Larger-than-life, a monster of mercurial moods- comic and menacing by turns- Stomboli is one of Disney's most three-dimensional and frightening villains.

"Bill was powerful muscular, high-strung and sensitive, with a tremendous ego." wrote Disney animators Frank Thomas and Ollie Johnston in their book The Disney Villain. "Everything was 'feelings' with Bill. Whatever he animated had the inner feelings of his characters expressed through very strong acting. He did not just get inside Stromboli, he was Stromboli and he lived that part."

In a Mickey Mouse short released in 1938, "Brave Little Tailor, Tytla animated the giant who was as dumb as he was huge. The character "became the model for all giants throughout the industry from gags to personality," according to Ollie Johnston and Frank Thomas. This film also sports great animation of Mickey by Fred Moore.

Early in 1938, Tytla animated the old magician in The Sorcerer's Apprentice, which would eventually become a segment in Fantasia. The character from Fantasia he is more known for of coarse is Chernobog the black god from the "Night on Bald Mountain" sequence. It's often said that Chernobog was based on actor Bela Lugosi, and Walt did bring him in to do live action reference for the character. Bill however already had a pretty good idea of what he wanted to do and didn't like Bela's interpretation of the character. In stead he had Wilfred Jackson act out the part for him and thats what he used as live action reference. The scene is pure pantomime, but shows the full emotional range of the character, from unabashed glee to profound despair, expressing physical pain at the sound of the church bells at dawn. Chernobog is considered Tytla's supreme achievement in personality animation and marks the zenith of his career.