This is one of the many, many, Looney Tunes "Merry Melodies" shorts.  It is also the best, as well as one of the best animated shorts that I have ever seen.

The story concerns a theme with which we are all familiar - an object that at first seems to be wonderful and offer great things ends up ruining a man's life.  In this case, of course, the object is a frog.  

Chuck Jones' work is truly impressive here.  The timing in the short is absolutely impeccable, from the frog's ability to the expected Tunes slapstick, and the great old Al Jolson songs are excellent as well.  The animation is probably the funniest stuff I have ever seen.  The frog looks absolutely hilarious, and the reaction shots of humans are done just as well.  Most frames of the film would in themselves be hysterical, I imagine.

In any case, I give this a four stars out of four, a perfect rating.  Everything about it is impeccable.  Oh to have been alive in the times when they would play this before movies instead of Mazda ads.

Be advised that said Looney Tunes short has no Looney Tunes in it.  

Is this the one where the guy finds the frog and it sings "Hello My Darlings...", but as soon as he shows someone - it reverts to a regular frog?

If that's the one - you are right. That is a classic.

MacDuff,

That's the one.

Has anyone else seen this?