Ghosts appear to be purple phantasmal beings with a defined head, arms and a thin body. Their head seems to have a snout and two ears that are pig-like. They lack any additional facial features.
The ghosts' arms are seen as about the same width as their body. Their hands have two visible fingers.
A certain being led an army of ghosts into battle in an attempt to invade the city on the mountain, where the birds ruled. To protect themselves from the invading ghosts, the birds hung a curtain around the mountain, but this caused the sun, the bird's source of power, to wane. The birds were eventually pushed to Sky Town, where the evil being allowed them to live. Any bird caught outside of Sky Town was in danger of being carried away by the ghosts.
Ghosts are entirely invincible and are not affected by fire shots, ice shots or divebombing.
Main Article: Ghost Ambush.
In the game, ghosts may be spawned randomly into a certain screen if the protagonist is traversing an area other than Sky Town. This event is triggered after the bandit is carried off by the ghosts in FireCage, where the entity warns the protagonist that if he is caught existing outside of Sky Town, he too will be caught.
When a "ghost capture" event occurs, the in-game screen glows purple, and the music changes to "Ghosts". One to four ghosts enters from one side of the screen and starts moving towards the bird. If a ghost makes contact with the bird during the in-game capture, he will sustain a certain amount of damage. The ghost chase is halted when the player moves to an adjacent screen. Ghosts do not necessarily respawn immediately if the screen where the chase began is reentered. Ghost captures will not occur in SkyTown.
The enemies in FinalClimb are entirely comprised of ghosts. They exhibit the same behaviour as during the bird's capture though they do not allow the bird to jump off them on contact. The bird may remain stuck on top of the ghost until he moves to the next screen. Unlike the ghosts that are randomly spawned into some areas, ghosts in FinalClimb begin in fixed positions on the screen. When the bird enters, the ghosts break from their spots and start to follow him until he leaves the screen.