Knife-kite

The Knife-kite is a type of non-sapient airborne predator native to the skies of Titan. It is about the size and shape of a pterosaur, and armed with a three-foot-long beak which it uses to impale prey. Its name comes from the fact that it doesn't actually fly, but simply glides in the currents like a kite, landing only when there's no wind or when it manages a kill. It is a dangerous beast, known to attack human settlers, but its very nature renders it unable to fly upwind.

Appearances

 * "Flight on Titan", by Stanley G. Weinbaum (1935)
 * "The Mad Moon", by Stanley G. Weinbaum (1935)