The Jitterbug was a song that was cut from from the original film, The Wizard of Oz (1939). It was the Wicked Witch, rather than the Nome King, who would have sent the creature after Dorothy's crew.
Theatrically released in Japan
The Field Mice play a crucial role in the first Oz book, where they pull the sleeping Lion on a pulley cart out of the poppy field. In The Wizard of Oz (1939) this was replaced by Glinda creating a snowfall. This cartoon is a rare on-screen appearance of the Field Mice.