Phantom

Phantoms, previously known as the Monster of the Night Skies and Mob B, are flying Hostile Mobs set to be added in the upcoming Update Aquatic.

Spawning
This mob will spawn in groups at a high altitude. The number in a group is as yet unknown.

Offense
Phantoms will attack by swooping down to bite the Player. According to information released so far, it will be attracted to Players with "insomnia"—those who haven’t slept in many Minecraft days.

Trivia

 * Phantoms were the second choice, and subsequent winner, of a Minecon Earth poll where fans of Minecraft could choose which new Mob of four they wanted added to the game.
 * When a Player dies, the insomnia the Player gets is reset, meaning that Phantoms will not target them until insomnia has been reattained.
 * On January 20, 2018, Jeb announced in a livestream that the mob's official name would be the Phantom.
 * Phantoms resemble and seem to have been based off a manta ray, an aquatic creature.
 * This will be the first naturally spawning hostile flying Overworld mob.
 * Vexes are flying hostile Mobs, but they only spawn when summoned by an Evoker.
 * Ghasts only spawn in the Nether.