MGM's Oscar nominated short animation Puss Gets the Boot (1940) was a pilot that propelled Tom and Jerry into animation history.

In this pilot, Tom (the cat named Jasper) is tormented by Jerry (the mouse named Jinx) after Tom's been warned by Mammy Two Shoes not to knock over or harm another item in the house or else! Jinx takes pleasure in this and tries to knock over various items so that Jasper gets the boot from the house and Jinx gets the run of the house. And we all know that Tom always has real trouble not getting in his fair share of trouble, so the rest is set in animation history and a prelude that sets the tone of every Tom and Jerry to come.

MGM's Tom and Jerry cartoons were headed by William Hanna and Joseph Barbera, who sought a better name for the duo and a year later in 1941 after a hat drawing, the duo was named Tom and Jerry (the name of a popular Christmastime drink). The very next episode almost a year later, the duo appeared as Tom and Jerry in the cartoon The Midnight Snack.

More Info: en.wikipedia.org