What is the Looney Tunes cartoon which says-get me a mouse George?

You'll find the phrase used by the dimwitted cat named "Benny" in the 1952 Looney Tunes cartoon "Hoppy Go Lucky".

The parody of Lennie & George (The characters are from John Steinbeck's novel "Of Mice and Men" ) showed up numerous times as in "Hiawatha's Rabbit Hunt" - "Falling Hare" - "The Abominable Snow Rabbit" - "Spaced Out Bunny" - "Of Fox and Hounds" (1940) - "Lonesome Lenny" (1946) - "Hoppy Go Lucky" (1952) - "Cat-Tails for Two" (1953) and "The Abominable Snow Rabbit" (1961) .