Giant Flying Manta

The Manta Ray or Kite are placeholder names given to a large flying creature that roams the world.

Behavior
The manta glides through the sky, often accompanied by swarms of small bird creatures. It is passive and seems immune to attacks, so its current purpose seems to be merely decoration. You can jump on top of it (provided you get high enough to be above it), and can fly around wherever it chooses to go. Doing so generally requires a jetpack.