"Upsy" Duck (real name unknown) was an anthropomorphic duck.
The sleepy-eyed but quick-footed Upsy Duck was an uncle of Donald Duck who was, in his nephew's own words, "a wow of a mountain climber". The peak of his career was becoming the first man to climb to the top of Mount Stratoshaft, in Switzerland. Unfortunately, while he was standing on top of the mountain, the wind caught his hat and carried it to the top of a small ice hill called the "Matterthorn" down in the valley. Upsy, due to the ice's slipperiness, was unable to climb to the top of the Matterthorn to retrieve his headwear, and he was disgraced. Nevertheless, the city of Duckburg decided to pay a discreet tribute to Upsy's earlier feats by naming a dinky dead-end alley after him. Much later, in 1965, Donald Duck set out to clear the name of Duck by mastering the Matterthorn himself.
Uncle Upsy Duck is featured in the 1965 story Mastering the Matterthorn.