I love Paul Simon's "The Obvious Child". It has nothing to do with dogs (except for one brief line) or costume parties, but it's very bouncy.

There's also They Might Be Giants' "Hot Dog", which is the end theme for the recent "Mickey Mouse Clubhouse". It's a cute, upbeat song. "Fibber Island" is another fun piece, all about telling outrageous stories. Ooo, and ditto for "Fake-Believe".

You could go with jazzy, mostly-instrumental, for the Muppet's "Mahna Mahna". Or more story/lyric oriented with "Moving Right Along".

That's...probably enough babbling for now. I tried?