The first Tom & Jerry cartoon.
Tom & Jerry were originally named "Jasper & Jinx" by William Hanna and Joseph Barbera. Only Tom was ever identified on-screen by his original name ("Jasper"). The name Jinx was used by H&B in their television cartoon about the mice Pixie and Dixie and their adversary the feline Mr. Jinx.
Originally the name of Tom and Jerry was Jasper and Jinx. After the successful run of the first episode of the animated series, the creators, Hanna and Barbera, wanted to change the names of the two protagonists. For this, they organized an intra-studio competition whereby employees suggested new names for the dynamic duo. John Carr, an animator, suggested the names Tom and Jerry and won $50 for it. At that time, Tom and Jerry was the name of a Christmas time mixed drink
This is when Tom and Jerry were called "Jasper and Jinx". Tom is called "Jasper" by the other female character in the story; and as with all Tom and Jerry cartoons were not really sure what Jerry's name is; as none of the other characters address him by a name; he's just a mouse; and the credits indicate he's Jerry (originally Jinx).
First-ever entry of long running Tom & Jerry franchise.