Providing a significant change in pace from the traditional United States coin designs, the Shield Nickel portrays neither animal, nor person.
The shield nickel first appeared in 1866, replacing the earlier Seated Liberty Half Dime. The "Half Dime" named denomination was dropped. Since the new five cent coins were to be made of nickel, the name caught on.
The design, created by James Longacre, is almost sterile in appearance. The coin's obverse depicts the traditional Union Shield. At the top of the shield is a likeness of the cross of the Order of Calatrava. The sides of the shield are held in by a wreath. "IN GOD WE TRUST" appears along the top, while the year is displayed at the bottom.
The reverse of the coin is equally sparse, with a large "5" in the middle, noting the value. Circling the number 5 is a pattern of thirteen stars alternating with thirteen sets of rays. In 1867, the coin's design was modified slightly by simply removing the rays on the reverse.
The sparse, sterile design of the coin might be attributed to the Civil War. Since the war ended in 1865, the feelings between the north and the south were still unsettling with one another. The country wasn't happy with itself, and the coin seems to reflect the mood of that time.
It's worth noting that the initial reverse design of the coin sparked controversy, as people believed the stars and the rays reflected the Confederate "Stars and Bars" design. I'd imagine this pissed off a few conspiracy theorists.
United States Coinage