The Oregon mascot had something to do with a duck in the early part of the century. Some say the name Webfoot was used as early as 1890. Officially, Webfoot became the name used for Oregon athletics in 1926. But it wasn’t long before students and fans realized webfeet were part of a duck and a duck named Puddles was adopted as the mascot.
In 1978, a student cartoonist developed a Mallard duke image, but that wasn’t exactly what the students wanted. Instead they chose Donald duck as a mascot.
Donald Duck belonged to Disney studios. As luck would have it, the UofO athletic director knew someone at Disney and he and Disney over a handshake gave UofO permission for the use of Donald Duck, in 1947.
In 1970, Disney lawyers questioned the use. The UofO had a photo showing the athletic director and Disney in matching jackets with the Donald Duck logo. That satisfied the legal counsel. And in 1973 a formal agreement was reached. In 2010 that agreement was expanded to allow Donald Duck to make public appearance.
(Information based on Wikipedia information)