Who is known for their stretchy characters and animated Gator in Fantasia?

The correct answer is Eric Larson, who is recognized for his distinctive animation style that emphasized the use of stretchy and exaggerated characters. This technique contributed to a sense of fluidity and expressiveness in animation. Eric Larson was a key member of Disney's Nine Old Men, the group of animators who significantly shaped the artistry of animation during Disney’s golden age.

In "Fantasia," Larson's work is particularly notable in the sequence featuring the Dancing Alligators, where he incorporated elements of squash and stretch to bring life and character to the gators. This approach not only enhanced the comedic aspects of the animation but also showcased Larson's ability to blend artistry with storytelling, making the characters memorable and engaging.

The other animators listed each contributed significantly to the animation landscape, but their styles and notable works differ. Frank Thomas was renowned for his work on character performances, John Lounsbery was known for his contributions to character design and movement, and Wolfgang Reitherman was famous for directing and animating many iconic Disney films. However, Larson's legacy is particularly tied to the creation of lively, exaggerated characters, solidifying his recognition in the context of this question.