Whimsical antique American tinsmith-made weathervane and roof finial. The long forked/swallow-tailed flag at top has what I think is terrific movement in its silhouette and actually rotates around the tapered spire.
Four-part stacked iron and tin construction: square pyramidal base, turned collar and cup, hollow globe, and central rod with rotating pennant above. Remnant paint (black and later white) on some surfaces.
New York State, early 20th century.