Porky's Romance (1937)
Porky's Romance is a 1937 Looney Tunes cartoon that stars Porky Pig and for the first time, Petunia Pig. The cartoon deals with Porky trying to propose to Petunia and him getting rejected by Petunia. He proceeds to try to commit suicide, but ends up in a bizarre dream showing what would happen if he married Petunia.
More at Wikipedia.