Her Honor, the Mare (1943)

Popeye's nephews happen by just as the glue factory is rejecting a sorry looking horse and decide to take it home. They want to treat it as a house pet, despite the obvious problems; Popeye says no. They try to hide it, including painting a Hitler face on its rear and calling it a painter, but keep making mistakes like feeding it horseradish (great reaction shots). Finally, they hide the horse in the closet; Popeye comes out and says that they'll have to keep it now. We see why when she's sitting at the table with her four new foals.