Mob B

Mob B is the label given to the second of four mobs that were part of a poll associated with MineCon Earth, in which Minecraft fans could vote for which of the four mobs they wanted to see added to the game.

Mob B is a flying monster whose concept art makes it look like a manta ray. It has currently no name except for "the Monster of the Night Skies". It was described as spawning at high altitudes in groups, attacking by swooping down to bite the player. It is said that it will be attracted to players with "insomnia"–those who haven’t slept in many in-game days. In his pitch video, Jeb said that players might want to vote for Mob B because there really aren’t any flying monsters in the Overworld yet (excluding Bats or Parrots, which aren't monsters, or the Vex, which only appears when it is summoned by an Evoker, not as a natural spawn).

In the end, Mob B was the one that won the poll, and it is currently schedule to be added to the game with the Update Aquatic, which was also announced at Minecon Earth.