The phantom is a flying hostile mob that preys on players who have gone more than three in-game days without sleeping. They attack by swooping down on players and don't stay in one location for long, making them difficult to hit.
A sword is the greatest weapon for slaying a ghost, but you can also send in your tamed wolf. If all else fails, the ghost dislikes cats and will normally keep a 16-block distance from any feline. If your domesticated cat hisses, it will escape.
If the phantom is hit with a sword enchanted with smite or is afflicted by the instant health effect, it receives additional damage. They are, however, poison resistant and can reverse the effects of quick damage potions.
Phantoms appear in the Overworld at night or during storms. Because they always spawn above you, it's very tough to dodge these nasty animals.
You must be just above sea level and not have a block overhead that blocks light in order to create a ghost. You should expect to hear one to six phantoms cry when they spawn 20-34 blocks above you.
If you kill a phantom, it will fall to the ground, allowing you to quickly collect the rewards: one to two phantom membranes and five experience orbs.
In Minecraft, you can employ phantom membranes to create medicines such as the Potion of Slow Falling.