Imogene the Cow

Origin
In the original stage production, L. Frank Baum replaced Toto with Imogen the Cow. Later, in the 1910 film, The Wonderful Wizard of Oz, the cow went to Oz with Dorothy Gale, Toto, and Hank the Mule.

Public Domain Appearances
Stage:
 * The Wizard of Oz

Film:
 * The Wonderful Wizard of Oz