The Aristo-Cat is a 1943 Merrie Melodies cartoon directed by Chuck Jones. It features the debut of Hubie and Bertie. The short also contains an early prototype version of who would later be known as Claude Cat.
Meadows, a butler is tired of the constant practical jokes of the family cat, Pussy, so much that he decides to quit his own job. The cat doesn't know what a mouse looks like, so when Hubie and Bertie show up, he gets terrified. At the end, the main problem was revealed to be a dream.